All Questions
Tagged with expression-construction expression-manipulation
16
questions
-1
votes
1
answer
51
views
Swap Composite Command Components
Let's take a composite Mathematica command:
A[B[]]
where A and B - two arbitrary ...
- 2,444
1
vote
1
answer
74
views
1
vote
1
answer
120
views
How to convert this Mathematica expression to another, as described here?
I am working on a function of which the core will consist of something like:
...
- 9,677
1
vote
2
answers
194
views
How to sort out/ extract positive and negative powers as list?
I have the following expression
expr = x1^d1 * x2^d2 * x3^d3;
where d1,d2,d3 can contain negative values/expression i.e. in ...
- 1,897
3
votes
0
answers
183
views
Computations with OptimizedExpressions without completely expanding them
I have to manipulate huge expressions that are rational functions of many (∼30) variables with integer coefficients. Storing them just as a ratio of two polynomials would be impractical. But they can ...
- 7,273
2
votes
0
answers
60
views
How to do an arbitrary expression growth in Mathematica?
I want to write a function that can be used to grow an expression from a seed or another existing expression based on part specification.
...
- 9,523
0
votes
1
answer
134
views
How to pass an expression as list elements for a Mathematica command
I'm trying to build a generic function that will calculate sums on different iterators.
To simplify let consider:
...
- 3
0
votes
0
answers
65
views
Transform String to Expression [duplicate]
I have a variable postVector and another called CHKpostVector. Both are global variables.
Only the variable ...
- 159
4
votes
3
answers
327
views
Handling multi-part equations
How are multi-part equations best handled? For example, take the torsion equation:
We could express part of this equation like this:
...
- 4,102
0
votes
1
answer
66
views
Misunderstanding of Replace code
I am looking for the right way to replace $\delta \, \, \text{by} \, \, 0.05 \, \, \, \beta \, \, \, \text{by} \, \, \, 1.77 \, \, \, \text{and} \, \, \, n \, \, \, \text{by} \, \, \, 12$ in this ...
- 411
1
vote
2
answers
79
views
Subsituting expressions for expressions
I'm trying to define functions using other functions, like so:
f[a_, b_] := a/b;
a[c_] := c;
b[d_] := d;
Now what I want to be able to do is two things:
...
- 45
2
votes
1
answer
1k
views
How to parse string to expression? [closed]
When trying to make a string an expression I see some wrong results:
...
- 1,748
3
votes
1
answer
194
views
Write Integer powers as products
I need to wirte all occasions of
(a+b)^3,Ftp^2, Sin[th]^2, ...etc
as
(a+b)*(a+b)*(a+b), Ftp*Ftp, Sin[th]*Sin[th], ...etc
...
- 410
7
votes
4
answers
815
views
Concatenating strings, unevaluated expressions and evaluated expressions/values
Maybe this is something very simple to some of you. Anyway, I think this can be useful to many others like me.
I would like to build an output that involves strings, unevaluated expressions and ...
- 1,101
2
votes
1
answer
121
views
expression contained across multiple cells
Is it possible to span one expression across multiple cells? E.g. long if statement or function evaluation. I looked in documentation and searched forum/google and could not find.
- 972