Intersection between two straight lines?

Clash Royale CLAN TAG#URR8PPP

up vote
3
down vote

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I'm specifically interested in the case in which lines AB and CD intersect, but outside (of at least one) of the segments AB, CD, and get the intersection I for further work. The similar questions only handle the case in which the segments intersect.

tikz-pgf

share|improve this question

asked 6 hours ago

vonbrand

3,51811128

• 
  
  
  

  
  

  
  
  
  
  
  

  
  see (tex.stackexchange.com/questions/31398/…)
  – Denis
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Pleasssse add a minimal working example! With 3.5k rep how can you not know the drill?
  – Andrew
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Denis, there the intersection is inside both segments.
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand, in the answer is inside too if you read it carefully.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @koleygr, I did try to decypher the answers, they mostly handle just the case (no interest to me) when the intersection is inside both segments, or perpendicular lines (in my case, they intersect outside the segments,at any angle)-
  – vonbrand
  2 hours ago
  
  

  
  
  
  

 | 
show 1 more comment

up vote
3
down vote

favorite

I'm specifically interested in the case in which lines AB and CD intersect, but outside (of at least one) of the segments AB, CD, and get the intersection I for further work. The similar questions only handle the case in which the segments intersect.

tikz-pgf

share|improve this question

asked 6 hours ago

vonbrand

3,51811128

• 
  
  
  

  
  

  
  
  
  
  
  

  
  see (tex.stackexchange.com/questions/31398/…)
  – Denis
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Pleasssse add a minimal working example! With 3.5k rep how can you not know the drill?
  – Andrew
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Denis, there the intersection is inside both segments.
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand, in the answer is inside too if you read it carefully.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @koleygr, I did try to decypher the answers, they mostly handle just the case (no interest to me) when the intersection is inside both segments, or perpendicular lines (in my case, they intersect outside the segments,at any angle)-
  – vonbrand
  2 hours ago
  
  

  
  
  
  

 | 
show 1 more comment

up vote
3
down vote

favorite

up vote
3
down vote

favorite

I'm specifically interested in the case in which lines AB and CD intersect, but outside (of at least one) of the segments AB, CD, and get the intersection I for further work. The similar questions only handle the case in which the segments intersect.

tikz-pgf

share|improve this question

asked 6 hours ago

vonbrand

3,51811128

I'm specifically interested in the case in which lines AB and CD intersect, but outside (of at least one) of the segments AB, CD, and get the intersection I for further work. The similar questions only handle the case in which the segments intersect.

tikz-pgf

tikz-pgf

share|improve this question

asked 6 hours ago

vonbrand

3,51811128

share|improve this question

asked 6 hours ago

vonbrand

3,51811128

share|improve this question

share|improve this question

asked 6 hours ago

vonbrand

3,51811128

asked 6 hours ago

vonbrand

3,51811128

asked 6 hours ago

vonbrand

3,51811128

3,51811128

• 
  
  
  

  
  

  
  
  
  
  
  

  
  see (tex.stackexchange.com/questions/31398/…)
  – Denis
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Pleasssse add a minimal working example! With 3.5k rep how can you not know the drill?
  – Andrew
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Denis, there the intersection is inside both segments.
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand, in the answer is inside too if you read it carefully.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @koleygr, I did try to decypher the answers, they mostly handle just the case (no interest to me) when the intersection is inside both segments, or perpendicular lines (in my case, they intersect outside the segments,at any angle)-
  – vonbrand
  2 hours ago
  
  

  
  
  
  

 | 
show 1 more comment

• 
  
  
  

  
  

  
  
  
  
  
  

  
  see (tex.stackexchange.com/questions/31398/…)
  – Denis
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  Pleasssse add a minimal working example! With 3.5k rep how can you not know the drill?
  – Andrew
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @Denis, there the intersection is inside both segments.
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand, in the answer is inside too if you read it carefully.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @koleygr, I did try to decypher the answers, they mostly handle just the case (no interest to me) when the intersection is inside both segments, or perpendicular lines (in my case, they intersect outside the segments,at any angle)-
  – vonbrand
  2 hours ago
  
  

  
  
  
  

see (tex.stackexchange.com/questions/31398/…)
– Denis
5 hours ago

see (tex.stackexchange.com/questions/31398/…)
– Denis
5 hours ago

5

5

Pleasssse add a minimal working example! With 3.5k rep how can you not know the drill?
– Andrew
5 hours ago

Pleasssse add a minimal working example! With 3.5k rep how can you not know the drill?
– Andrew
5 hours ago

@Denis, there the intersection is inside both segments.
– vonbrand
5 hours ago

@Denis, there the intersection is inside both segments.
– vonbrand
5 hours ago

@vonbrand, in the answer is inside too if you read it carefully.
– koleygr
5 hours ago

@vonbrand, in the answer is inside too if you read it carefully.
– koleygr
5 hours ago

@koleygr, I did try to decypher the answers, they mostly handle just the case (no interest to me) when the intersection is inside both segments, or perpendicular lines (in my case, they intersect outside the segments,at any angle)-
– vonbrand
2 hours ago

@koleygr, I did try to decypher the answers, they mostly handle just the case (no interest to me) when the intersection is inside both segments, or perpendicular lines (in my case, they intersect outside the segments,at any angle)-
– vonbrand
2 hours ago

 | 
show 1 more comment

2 Answers
2

active

oldest

votes

up vote
5
down vote

1. Declare two path which intersect.


2. Computes and draw the intersection point.


3. Draw (or not) some fragment of original paths.

That's all.

documentclass[tikz,border=2mm]standalone 
usetikzlibraryintersections, calc

begindocument
begintikzpicture
path[name path=a] (0,0) coordinate (a1) -- (2,4) coordinate (a2);
path[name path=b] (0,4) coordinate (b1) -- (5,2) coordinate (b2);
fill[red,name intersections=of=a and b]
 (intersection-1) circle (2pt);

draw (a1)--($(a1)!.5!(a2)$);
draw (b2)--($(b2)!.5!(b1)$);
endtikzpicture
enddocument

share|improve this answer

answered 5 hours ago

Ignasi

87k4155289

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Weird... I tried something very similar, got nowhere...
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  (+1) The funny think is the optical illusion that the dot in over their intersection.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Nope. The intersection is inside the segments a1-a2 and b1-b2.
  – vonbrand
  2 hours ago
  

  
  
  
  

add a comment | 

up vote
4
down vote

There is another way to find the intersection of two intersecting lines that is no longer documented in manual 3.0.1a but still works.
It is on page 87 of manual 1.18 which you will find here (until when?): tikz pgf manual 1.18

It consists in solving a system of 2 equations with 2 unknowns (the points that define the 2 lines). It is not necessary for the paths to intersect on the figure to find their intersection unlike the version given in manual 3.01a of the solution given by ignasi.
The second advantage is that it is not necessary to load any library for this to work.

You will notice that the points or their coordinates are named without parentheses:

intersection of A--B and 0,3--2,2

Line A--B shorter as suggested by @marmot

documentclass[tikz,border=2mm]standalone 
begindocument
begintikzpicture
draw[help lines] (0,0) grid (3,3);
draw (0,0) coordinate (A)node[below]A -- (2,1.5) coordinate (B)node[below right]B
(0,3)node[below left]C -- (2,2)node[below left]D;
fill[blue] (intersection of A--B and 0,3--2,2) circle (2pt);
endtikzpicture
enddocument

Translated with www.DeepL.com/Translator

share|improve this answer

edited 2 hours ago

answered 4 hours ago

AndréC

3,124728

• 
  
  
  

  
  

  
  
  
  
  
  

  
  @marmot, I don't know more than the given points A, B, C, D. Just drawing part of the line is no help.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand Finally, I don't know if I understood your question correctly. Have you read the update of my answer?
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I believe this is deprecated in current TikZ... there is no section 1.18 in current version 3.0.1a of the TikZ & PGF manual. Page 118 gives an example of segments that do intersect.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand No, it works. it had been deleted, then at the request of the users, it was delivered (but without the doc). it's not the only thing like that with tikz, there is also shorten > which still works but is only documented in the manual 1.18.
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand It is still official, though with a slightly different syntax. See page 118 (instead of section 1.18) of the pgfmanual. Try draw (0,0) coordinate(A) -- (1,2) coordinate(B); draw (3.5,0) coordinate(C)-- (3,2) coordinate(D); coordinate (X) at (intersection cs:first line=(A)--(B), second line=(C)--(D)); fill[red] (X) circle (1pt);.
  – marmot
  1 hour ago
  

  
  
  
  

add a comment | 

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2 Answers
2

active

oldest

votes

2 Answers
2

active

oldest

votes

active

oldest

votes

active

oldest

votes

up vote
5
down vote

1. Declare two path which intersect.


2. Computes and draw the intersection point.


3. Draw (or not) some fragment of original paths.

That's all.

documentclass[tikz,border=2mm]standalone 
usetikzlibraryintersections, calc

begindocument
begintikzpicture
path[name path=a] (0,0) coordinate (a1) -- (2,4) coordinate (a2);
path[name path=b] (0,4) coordinate (b1) -- (5,2) coordinate (b2);
fill[red,name intersections=of=a and b]
 (intersection-1) circle (2pt);

draw (a1)--($(a1)!.5!(a2)$);
draw (b2)--($(b2)!.5!(b1)$);
endtikzpicture
enddocument

share|improve this answer

answered 5 hours ago

Ignasi

87k4155289

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Weird... I tried something very similar, got nowhere...
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  (+1) The funny think is the optical illusion that the dot in over their intersection.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Nope. The intersection is inside the segments a1-a2 and b1-b2.
  – vonbrand
  2 hours ago
  

  
  
  
  

add a comment | 

up vote
5
down vote

1. Declare two path which intersect.


2. Computes and draw the intersection point.


3. Draw (or not) some fragment of original paths.

That's all.

documentclass[tikz,border=2mm]standalone 
usetikzlibraryintersections, calc

begindocument
begintikzpicture
path[name path=a] (0,0) coordinate (a1) -- (2,4) coordinate (a2);
path[name path=b] (0,4) coordinate (b1) -- (5,2) coordinate (b2);
fill[red,name intersections=of=a and b]
 (intersection-1) circle (2pt);

draw (a1)--($(a1)!.5!(a2)$);
draw (b2)--($(b2)!.5!(b1)$);
endtikzpicture
enddocument

share|improve this answer

answered 5 hours ago

Ignasi

87k4155289

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Weird... I tried something very similar, got nowhere...
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  (+1) The funny think is the optical illusion that the dot in over their intersection.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Nope. The intersection is inside the segments a1-a2 and b1-b2.
  – vonbrand
  2 hours ago
  

  
  
  
  

add a comment | 

up vote
5
down vote

up vote
5
down vote

1. Declare two path which intersect.


2. Computes and draw the intersection point.


3. Draw (or not) some fragment of original paths.

That's all.

documentclass[tikz,border=2mm]standalone 
usetikzlibraryintersections, calc

begindocument
begintikzpicture
path[name path=a] (0,0) coordinate (a1) -- (2,4) coordinate (a2);
path[name path=b] (0,4) coordinate (b1) -- (5,2) coordinate (b2);
fill[red,name intersections=of=a and b]
 (intersection-1) circle (2pt);

draw (a1)--($(a1)!.5!(a2)$);
draw (b2)--($(b2)!.5!(b1)$);
endtikzpicture
enddocument

share|improve this answer

answered 5 hours ago

Ignasi

87k4155289

1. Declare two path which intersect.


2. Computes and draw the intersection point.


3. Draw (or not) some fragment of original paths.

That's all.

documentclass[tikz,border=2mm]standalone 
usetikzlibraryintersections, calc

begindocument
begintikzpicture
path[name path=a] (0,0) coordinate (a1) -- (2,4) coordinate (a2);
path[name path=b] (0,4) coordinate (b1) -- (5,2) coordinate (b2);
fill[red,name intersections=of=a and b]
 (intersection-1) circle (2pt);

draw (a1)--($(a1)!.5!(a2)$);
draw (b2)--($(b2)!.5!(b1)$);
endtikzpicture
enddocument

share|improve this answer

answered 5 hours ago

Ignasi

87k4155289

share|improve this answer

share|improve this answer

answered 5 hours ago

Ignasi

87k4155289

answered 5 hours ago

Ignasi

87k4155289

answered 5 hours ago

Ignasi

87k4155289

87k4155289

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Weird... I tried something very similar, got nowhere...
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  (+1) The funny think is the optical illusion that the dot in over their intersection.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Nope. The intersection is inside the segments a1-a2 and b1-b2.
  – vonbrand
  2 hours ago
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  Weird... I tried something very similar, got nowhere...
  – vonbrand
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  (+1) The funny think is the optical illusion that the dot in over their intersection.
  – koleygr
  5 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  Nope. The intersection is inside the segments a1-a2 and b1-b2.
  – vonbrand
  2 hours ago
  

  
  
  
  

Weird... I tried something very similar, got nowhere...
– vonbrand
5 hours ago

Weird... I tried something very similar, got nowhere...
– vonbrand
5 hours ago

1

1

(+1) The funny think is the optical illusion that the dot in over their intersection.
– koleygr
5 hours ago

(+1) The funny think is the optical illusion that the dot in over their intersection.
– koleygr
5 hours ago

Nope. The intersection is inside the segments a1-a2 and b1-b2.
– vonbrand
2 hours ago

Nope. The intersection is inside the segments a1-a2 and b1-b2.
– vonbrand
2 hours ago

add a comment | 

up vote
4
down vote

There is another way to find the intersection of two intersecting lines that is no longer documented in manual 3.0.1a but still works.
It is on page 87 of manual 1.18 which you will find here (until when?): tikz pgf manual 1.18

It consists in solving a system of 2 equations with 2 unknowns (the points that define the 2 lines). It is not necessary for the paths to intersect on the figure to find their intersection unlike the version given in manual 3.01a of the solution given by ignasi.
The second advantage is that it is not necessary to load any library for this to work.

You will notice that the points or their coordinates are named without parentheses:

intersection of A--B and 0,3--2,2

Line A--B shorter as suggested by @marmot

documentclass[tikz,border=2mm]standalone 
begindocument
begintikzpicture
draw[help lines] (0,0) grid (3,3);
draw (0,0) coordinate (A)node[below]A -- (2,1.5) coordinate (B)node[below right]B
(0,3)node[below left]C -- (2,2)node[below left]D;
fill[blue] (intersection of A--B and 0,3--2,2) circle (2pt);
endtikzpicture
enddocument

Translated with www.DeepL.com/Translator

share|improve this answer

edited 2 hours ago

answered 4 hours ago

AndréC

3,124728

• 
  
  
  

  
  

  
  
  
  
  
  

  
  @marmot, I don't know more than the given points A, B, C, D. Just drawing part of the line is no help.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand Finally, I don't know if I understood your question correctly. Have you read the update of my answer?
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I believe this is deprecated in current TikZ... there is no section 1.18 in current version 3.0.1a of the TikZ & PGF manual. Page 118 gives an example of segments that do intersect.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand No, it works. it had been deleted, then at the request of the users, it was delivered (but without the doc). it's not the only thing like that with tikz, there is also shorten > which still works but is only documented in the manual 1.18.
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand It is still official, though with a slightly different syntax. See page 118 (instead of section 1.18) of the pgfmanual. Try draw (0,0) coordinate(A) -- (1,2) coordinate(B); draw (3.5,0) coordinate(C)-- (3,2) coordinate(D); coordinate (X) at (intersection cs:first line=(A)--(B), second line=(C)--(D)); fill[red] (X) circle (1pt);.
  – marmot
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
4
down vote

There is another way to find the intersection of two intersecting lines that is no longer documented in manual 3.0.1a but still works.
It is on page 87 of manual 1.18 which you will find here (until when?): tikz pgf manual 1.18

It consists in solving a system of 2 equations with 2 unknowns (the points that define the 2 lines). It is not necessary for the paths to intersect on the figure to find their intersection unlike the version given in manual 3.01a of the solution given by ignasi.
The second advantage is that it is not necessary to load any library for this to work.

You will notice that the points or their coordinates are named without parentheses:

intersection of A--B and 0,3--2,2

Line A--B shorter as suggested by @marmot

documentclass[tikz,border=2mm]standalone 
begindocument
begintikzpicture
draw[help lines] (0,0) grid (3,3);
draw (0,0) coordinate (A)node[below]A -- (2,1.5) coordinate (B)node[below right]B
(0,3)node[below left]C -- (2,2)node[below left]D;
fill[blue] (intersection of A--B and 0,3--2,2) circle (2pt);
endtikzpicture
enddocument

Translated with www.DeepL.com/Translator

share|improve this answer

edited 2 hours ago

answered 4 hours ago

AndréC

3,124728

• 
  
  
  

  
  

  
  
  
  
  
  

  
  @marmot, I don't know more than the given points A, B, C, D. Just drawing part of the line is no help.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand Finally, I don't know if I understood your question correctly. Have you read the update of my answer?
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I believe this is deprecated in current TikZ... there is no section 1.18 in current version 3.0.1a of the TikZ & PGF manual. Page 118 gives an example of segments that do intersect.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand No, it works. it had been deleted, then at the request of the users, it was delivered (but without the doc). it's not the only thing like that with tikz, there is also shorten > which still works but is only documented in the manual 1.18.
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand It is still official, though with a slightly different syntax. See page 118 (instead of section 1.18) of the pgfmanual. Try draw (0,0) coordinate(A) -- (1,2) coordinate(B); draw (3.5,0) coordinate(C)-- (3,2) coordinate(D); coordinate (X) at (intersection cs:first line=(A)--(B), second line=(C)--(D)); fill[red] (X) circle (1pt);.
  – marmot
  1 hour ago
  

  
  
  
  

add a comment | 

up vote
4
down vote

up vote
4
down vote

There is another way to find the intersection of two intersecting lines that is no longer documented in manual 3.0.1a but still works.
It is on page 87 of manual 1.18 which you will find here (until when?): tikz pgf manual 1.18

It consists in solving a system of 2 equations with 2 unknowns (the points that define the 2 lines). It is not necessary for the paths to intersect on the figure to find their intersection unlike the version given in manual 3.01a of the solution given by ignasi.
The second advantage is that it is not necessary to load any library for this to work.

You will notice that the points or their coordinates are named without parentheses:

intersection of A--B and 0,3--2,2

Line A--B shorter as suggested by @marmot

documentclass[tikz,border=2mm]standalone 
begindocument
begintikzpicture
draw[help lines] (0,0) grid (3,3);
draw (0,0) coordinate (A)node[below]A -- (2,1.5) coordinate (B)node[below right]B
(0,3)node[below left]C -- (2,2)node[below left]D;
fill[blue] (intersection of A--B and 0,3--2,2) circle (2pt);
endtikzpicture
enddocument

Translated with www.DeepL.com/Translator

share|improve this answer

edited 2 hours ago

answered 4 hours ago

AndréC

3,124728

There is another way to find the intersection of two intersecting lines that is no longer documented in manual 3.0.1a but still works.
It is on page 87 of manual 1.18 which you will find here (until when?): tikz pgf manual 1.18

It consists in solving a system of 2 equations with 2 unknowns (the points that define the 2 lines). It is not necessary for the paths to intersect on the figure to find their intersection unlike the version given in manual 3.01a of the solution given by ignasi.
The second advantage is that it is not necessary to load any library for this to work.

You will notice that the points or their coordinates are named without parentheses:

intersection of A--B and 0,3--2,2

Line A--B shorter as suggested by @marmot

documentclass[tikz,border=2mm]standalone 
begindocument
begintikzpicture
draw[help lines] (0,0) grid (3,3);
draw (0,0) coordinate (A)node[below]A -- (2,1.5) coordinate (B)node[below right]B
(0,3)node[below left]C -- (2,2)node[below left]D;
fill[blue] (intersection of A--B and 0,3--2,2) circle (2pt);
endtikzpicture
enddocument

Translated with www.DeepL.com/Translator

share|improve this answer

edited 2 hours ago

answered 4 hours ago

AndréC

3,124728

share|improve this answer

share|improve this answer

edited 2 hours ago

edited 2 hours ago

edited 2 hours ago

answered 4 hours ago

AndréC

3,124728

answered 4 hours ago

AndréC

3,124728

answered 4 hours ago

AndréC

3,124728

3,124728

• 
  
  
  

  
  

  
  
  
  
  
  

  
  @marmot, I don't know more than the given points A, B, C, D. Just drawing part of the line is no help.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand Finally, I don't know if I understood your question correctly. Have you read the update of my answer?
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I believe this is deprecated in current TikZ... there is no section 1.18 in current version 3.0.1a of the TikZ & PGF manual. Page 118 gives an example of segments that do intersect.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand No, it works. it had been deleted, then at the request of the users, it was delivered (but without the doc). it's not the only thing like that with tikz, there is also shorten > which still works but is only documented in the manual 1.18.
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand It is still official, though with a slightly different syntax. See page 118 (instead of section 1.18) of the pgfmanual. Try draw (0,0) coordinate(A) -- (1,2) coordinate(B); draw (3.5,0) coordinate(C)-- (3,2) coordinate(D); coordinate (X) at (intersection cs:first line=(A)--(B), second line=(C)--(D)); fill[red] (X) circle (1pt);.
  – marmot
  1 hour ago
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  @marmot, I don't know more than the given points A, B, C, D. Just drawing part of the line is no help.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand Finally, I don't know if I understood your question correctly. Have you read the update of my answer?
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  I believe this is deprecated in current TikZ... there is no section 1.18 in current version 3.0.1a of the TikZ & PGF manual. Page 118 gives an example of segments that do intersect.
  – vonbrand
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand No, it works. it had been deleted, then at the request of the users, it was delivered (but without the doc). it's not the only thing like that with tikz, there is also shorten > which still works but is only documented in the manual 1.18.
  – AndréC
  2 hours ago
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  @vonbrand It is still official, though with a slightly different syntax. See page 118 (instead of section 1.18) of the pgfmanual. Try draw (0,0) coordinate(A) -- (1,2) coordinate(B); draw (3.5,0) coordinate(C)-- (3,2) coordinate(D); coordinate (X) at (intersection cs:first line=(A)--(B), second line=(C)--(D)); fill[red] (X) circle (1pt);.
  – marmot
  1 hour ago
  

  
  
  
  

@marmot, I don't know more than the given points A, B, C, D. Just drawing part of the line is no help.
– vonbrand
2 hours ago

@marmot, I don't know more than the given points A, B, C, D. Just drawing part of the line is no help.
– vonbrand
2 hours ago

@vonbrand Finally, I don't know if I understood your question correctly. Have you read the update of my answer?
– AndréC
2 hours ago

@vonbrand Finally, I don't know if I understood your question correctly. Have you read the update of my answer?
– AndréC
2 hours ago

I believe this is deprecated in current TikZ... there is no section 1.18 in current version 3.0.1a of the TikZ & PGF manual. Page 118 gives an example of segments that do intersect.
– vonbrand
2 hours ago

I believe this is deprecated in current TikZ... there is no section 1.18 in current version 3.0.1a of the TikZ & PGF manual. Page 118 gives an example of segments that do intersect.
– vonbrand
2 hours ago

@vonbrand No, it works. it had been deleted, then at the request of the users, it was delivered (but without the doc). it's not the only thing like that with tikz, there is also shorten > which still works but is only documented in the manual 1.18.
– AndréC
2 hours ago

@vonbrand No, it works. it had been deleted, then at the request of the users, it was delivered (but without the doc). it's not the only thing like that with tikz, there is also shorten > which still works but is only documented in the manual 1.18.
– AndréC
2 hours ago

@vonbrand It is still official, though with a slightly different syntax. See page 118 (instead of section 1.18) of the pgfmanual. Try draw (0,0) coordinate(A) -- (1,2) coordinate(B); draw (3.5,0) coordinate(C)-- (3,2) coordinate(D); coordinate (X) at (intersection cs:first line=(A)--(B), second line=(C)--(D)); fill[red] (X) circle (1pt);.
– marmot
1 hour ago

@vonbrand It is still official, though with a slightly different syntax. See page 118 (instead of section 1.18) of the pgfmanual. Try draw (0,0) coordinate(A) -- (1,2) coordinate(B); draw (3.5,0) coordinate(C)-- (3,2) coordinate(D); coordinate (X) at (intersection cs:first line=(A)--(B), second line=(C)--(D)); fill[red] (X) circle (1pt);.
– marmot
1 hour ago

add a comment | 

 

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