Problems with def

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I have created the following macros in LaTeX:

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

Where twomate is a 2x2 matrix, twoclmn creates a 2x1 column vector, and pwr is a command to raise the argument to the power.
However, if I try to do the following:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )$$

I get an error. However, if I replace the last entry with something that is not a def command:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),5 )$$

The document complies successfully. In addition, the following does not compile successfully:

$$twoclmn(frac625epwr(2t)-frac15tepwr(2t),-frac225epwr(2t) + frac25 t epwr(2t))$$

But the following does:

$$twoclmn(frac625e^2t-frac15te^2t,-frac225e^2t + frac25 t e^2t)$$

So the problem seems to be the nested def commands. How may I nest def commands, without the compiler complaining?

asked 4 hours ago

Hossmeister

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1
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I have created the following macros in LaTeX:

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

Where twomate is a 2x2 matrix, twoclmn creates a 2x1 column vector, and pwr is a command to raise the argument to the power.
However, if I try to do the following:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )$$

I get an error. However, if I replace the last entry with something that is not a def command:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),5 )$$

The document complies successfully. In addition, the following does not compile successfully:

$$twoclmn(frac625epwr(2t)-frac15tepwr(2t),-frac225epwr(2t) + frac25 t epwr(2t))$$

But the following does:

$$twoclmn(frac625e^2t-frac15te^2t,-frac225e^2t + frac25 t e^2t)$$

So the problem seems to be the nested def commands. How may I nest def commands, without the compiler complaining?

asked 4 hours ago

Hossmeister

New contributor

add a comment |

up vote
1
down vote

favorite

I have created the following macros in LaTeX:

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

Where twomate is a 2x2 matrix, twoclmn creates a 2x1 column vector, and pwr is a command to raise the argument to the power.
However, if I try to do the following:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )$$

I get an error. However, if I replace the last entry with something that is not a def command:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),5 )$$

The document complies successfully. In addition, the following does not compile successfully:

$$twoclmn(frac625epwr(2t)-frac15tepwr(2t),-frac225epwr(2t) + frac25 t epwr(2t))$$

But the following does:

$$twoclmn(frac625e^2t-frac15te^2t,-frac225e^2t + frac25 t e^2t)$$

So the problem seems to be the nested def commands. How may I nest def commands, without the compiler complaining?

asked 4 hours ago

Hossmeister

New contributor

I have created the following macros in LaTeX:

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

Where twomate is a 2x2 matrix, twoclmn creates a 2x1 column vector, and pwr is a command to raise the argument to the power.
However, if I try to do the following:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )$$

I get an error. However, if I replace the last entry with something that is not a def command:

$$twomate(3epwr(-3t),epwr(2t),-epwr(-3t),5 )$$

The document complies successfully. In addition, the following does not compile successfully:

$$twoclmn(frac625epwr(2t)-frac15tepwr(2t),-frac225epwr(2t) + frac25 t epwr(2t))$$

But the following does:

$$twoclmn(frac625e^2t-frac15te^2t,-frac225e^2t + frac25 t e^2t)$$

So the problem seems to be the nested def commands. How may I nest def commands, without the compiler complaining?

math-mode macros

asked 4 hours ago

Hossmeister

New contributor

asked 4 hours ago

Hossmeister

New contributor

asked 4 hours ago

Hossmeister

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asked 4 hours ago

Hossmeister

asked 4 hours ago

Hossmeister

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3 Answers
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active

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up vote
2
down vote

TeX's delimited parameters parsing doesn't take nesting into account properly. So if you call twomate(3epwr(-3t), ...), the final ) for twomate isn't found at the end of that line but at the end of pwr(-3t). The improperly formed call of pwr then causes trouble.

To hide nested calls of your commands, put them into ... groups (though this probably defeats the purpose):

documentclassarticle
usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

begindocument
[ twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t)) ]
enddocument

enter image description here

By the way, don't use $$ ... $$ for display math environments but LaTeX's or amsmath's variants like [ ... ].

edited 3 hours ago

answered 3 hours ago

siracusa

4,26911127

add a comment |

up vote
2
down vote

You can use xparse for this job, because the r argument type takes care of nesting.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,r()%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrr()^#1

begindocument

[
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )
]

enddocument

However, using () as delimiters doesn't seem a good idea. The following is as clear and behaves better with syntax coloring of front ends.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,m%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrm^#1

begindocument

[
twomate3epwr-3t,epwr2t,-epwr-3t,-2epwr2t
]

enddocument

enter image description here

answered 2 hours ago

egreg

696k8518473104

add a comment |

up vote
1
down vote

Your def contains a very specific sequence defined as the parameter text:

% 1 2 3 4 5
deftwomate(<1>,<2>,<3>,<4>) ... 
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └ comma ┘ │
% └─── bracket ───┘

This parameter text is matched exactly in order (almost like a first-come-first-served style) to extract the four arguments <1>, <2>, <3> and <4>. Here's how the elements are grabbed for twomate with the above notation:

% 1 2 3 4 5
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └────── comma ────────┘ │
% └───────────────── bracket ──────────────────┘

It should be clear that the last bracket ) isn't properly captured for pwr. The way around it is to hide pwr(.) from twomate:

documentclassarticle

usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1

begindocument

[
 twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
]

enddocument

This solves the problem only temporarily. If you nest elements, you'll run into similar problems because of the parameter text pattern matching. In general, it is safer to group arguments using ....

edited 3 hours ago

answered 3 hours ago

Werner

429k589401618

add a comment |

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3 Answers
3

active

oldest

votes

3 Answers
3

active

oldest

votes

up vote
2
down vote

To hide nested calls of your commands, put them into ... groups (though this probably defeats the purpose):

documentclassarticle
usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

begindocument
[ twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t)) ]
enddocument

enter image description here

By the way, don't use $$ ... $$ for display math environments but LaTeX's or amsmath's variants like [ ... ].

edited 3 hours ago

answered 3 hours ago

siracusa

4,26911127

add a comment |

up vote
2
down vote

To hide nested calls of your commands, put them into ... groups (though this probably defeats the purpose):

documentclassarticle
usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

begindocument
[ twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t)) ]
enddocument

enter image description here

By the way, don't use $$ ... $$ for display math environments but LaTeX's or amsmath's variants like [ ... ].

edited 3 hours ago

answered 3 hours ago

siracusa

4,26911127

add a comment |

up vote
2
down vote

To hide nested calls of your commands, put them into ... groups (though this probably defeats the purpose):

documentclassarticle
usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

begindocument
[ twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t)) ]
enddocument

enter image description here

By the way, don't use $$ ... $$ for display math environments but LaTeX's or amsmath's variants like [ ... ].

edited 3 hours ago

answered 3 hours ago

siracusa

4,26911127

To hide nested calls of your commands, put them into ... groups (though this probably defeats the purpose):

documentclassarticle
usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1
deftwoclmn(#1,#2)beginpmatrix#1\#2endpmatrix

begindocument
[ twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t)) ]
enddocument

enter image description here

By the way, don't use $$ ... $$ for display math environments but LaTeX's or amsmath's variants like [ ... ].

edited 3 hours ago

answered 3 hours ago

siracusa

4,26911127

edited 3 hours ago

answered 3 hours ago

siracusa

4,26911127

answered 3 hours ago

siracusa

4,26911127

answered 3 hours ago

siracusa

4,26911127

add a comment |

up vote
2
down vote

You can use xparse for this job, because the r argument type takes care of nesting.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,r()%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrr()^#1

begindocument

[
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )
]

enddocument

However, using () as delimiters doesn't seem a good idea. The following is as clear and behaves better with syntax coloring of front ends.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,m%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrm^#1

begindocument

[
twomate3epwr-3t,epwr2t,-epwr-3t,-2epwr2t
]

enddocument

enter image description here

answered 2 hours ago

egreg

696k8518473104

add a comment |

up vote
2
down vote

You can use xparse for this job, because the r argument type takes care of nesting.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,r()%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrr()^#1

begindocument

[
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )
]

enddocument

However, using () as delimiters doesn't seem a good idea. The following is as clear and behaves better with syntax coloring of front ends.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,m%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrm^#1

begindocument

[
twomate3epwr-3t,epwr2t,-epwr-3t,-2epwr2t
]

enddocument

enter image description here

answered 2 hours ago

egreg

696k8518473104

add a comment |

up vote
2
down vote

You can use xparse for this job, because the r argument type takes care of nesting.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,r()%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrr()^#1

begindocument

[
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )
]

enddocument

However, using () as delimiters doesn't seem a good idea. The following is as clear and behaves better with syntax coloring of front ends.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,m%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrm^#1

begindocument

[
twomate3epwr-3t,epwr2t,-epwr-3t,-2epwr2t
]

enddocument

enter image description here

answered 2 hours ago

egreg

696k8518473104

You can use xparse for this job, because the r argument type takes care of nesting.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,r()%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrr()^#1

begindocument

[
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t) )
]

enddocument

However, using () as delimiters doesn't seem a good idea. The following is as clear and behaves better with syntax coloring of front ends.

documentclassarticle
usepackageamsmath
usepackagexparse

NewDocumentCommandtwomate>SplitArgument3,m%
 maketwomate#1%

NewDocumentCommandmaketwomatemmmm%
 beginpmatrix#1&#2\#3&#4endpmatrix%

NewDocumentCommandpwrm^#1

begindocument

[
twomate3epwr-3t,epwr2t,-epwr-3t,-2epwr2t
]

enddocument

enter image description here

answered 2 hours ago

egreg

696k8518473104

answered 2 hours ago

egreg

696k8518473104

answered 2 hours ago

egreg

696k8518473104

answered 2 hours ago

egreg

696k8518473104

add a comment |

up vote
1
down vote

Your def contains a very specific sequence defined as the parameter text:

% 1 2 3 4 5
deftwomate(<1>,<2>,<3>,<4>) ... 
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └ comma ┘ │
% └─── bracket ───┘

% 1 2 3 4 5
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └────── comma ────────┘ │
% └───────────────── bracket ──────────────────┘

It should be clear that the last bracket ) isn't properly captured for pwr. The way around it is to hide pwr(.) from twomate:

documentclassarticle

usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1

begindocument

[
 twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
]

enddocument

This solves the problem only temporarily. If you nest elements, you'll run into similar problems because of the parameter text pattern matching. In general, it is safer to group arguments using ....

edited 3 hours ago

answered 3 hours ago

Werner

429k589401618

add a comment |

up vote
1
down vote

Your def contains a very specific sequence defined as the parameter text:

% 1 2 3 4 5
deftwomate(<1>,<2>,<3>,<4>) ... 
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └ comma ┘ │
% └─── bracket ───┘

% 1 2 3 4 5
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └────── comma ────────┘ │
% └───────────────── bracket ──────────────────┘

It should be clear that the last bracket ) isn't properly captured for pwr. The way around it is to hide pwr(.) from twomate:

documentclassarticle

usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1

begindocument

[
 twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
]

enddocument

This solves the problem only temporarily. If you nest elements, you'll run into similar problems because of the parameter text pattern matching. In general, it is safer to group arguments using ....

edited 3 hours ago

answered 3 hours ago

Werner

429k589401618

add a comment |

up vote
1
down vote

Your def contains a very specific sequence defined as the parameter text:

% 1 2 3 4 5
deftwomate(<1>,<2>,<3>,<4>) ... 
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └ comma ┘ │
% └─── bracket ───┘

% 1 2 3 4 5
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └────── comma ────────┘ │
% └───────────────── bracket ──────────────────┘

It should be clear that the last bracket ) isn't properly captured for pwr. The way around it is to hide pwr(.) from twomate:

documentclassarticle

usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1

begindocument

[
 twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
]

enddocument

This solves the problem only temporarily. If you nest elements, you'll run into similar problems because of the parameter text pattern matching. In general, it is safer to group arguments using ....

edited 3 hours ago

answered 3 hours ago

Werner

429k589401618

Your def contains a very specific sequence defined as the parameter text:

% 1 2 3 4 5
deftwomate(<1>,<2>,<3>,<4>) ... 
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └ comma ┘ │
% └─── bracket ───┘

% 1 2 3 4 5
twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
% ^ ^ ^ ^ ^
% │ │ │ │ │
% │ └────── comma ────────┘ │
% └───────────────── bracket ──────────────────┘

It should be clear that the last bracket ) isn't properly captured for pwr. The way around it is to hide pwr(.) from twomate:

documentclassarticle

usepackageamsmath

deftwomate(#1,#2,#3,#4)beginpmatrix#1&#2\#3&#4endpmatrix
defpwr(#1)^#1

begindocument

[
 twomate(3epwr(-3t),epwr(2t),-epwr(-3t),-2epwr(2t))
]

enddocument

This solves the problem only temporarily. If you nest elements, you'll run into similar problems because of the parameter text pattern matching. In general, it is safer to group arguments using ....

edited 3 hours ago

answered 3 hours ago

Werner

429k589401618

edited 3 hours ago

answered 3 hours ago

Werner

429k589401618

answered 3 hours ago

Werner

429k589401618

answered 3 hours ago

Werner

429k589401618

add a comment |

Hossmeister is a new contributor. Be nice, and check out our Code of Conduct.

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