All Questions
Tagged with replacement expression-manipulation
75
questions
2
votes
2
answers
89
views
Formal substitution of exponential factors in an expression
Assume that we have some complex algebraic expression, like
Exp[(a t + b s)/w] ( t Exp[ q t] w + q Exp[q s] Exp[-2 s] + a^2 Exp[3 s] + s t + 1 )
Now, this is just ...
- 143
0
votes
0
answers
96
views
How to rearrange terms in an expression to a particular form (e.g. A/w-> A*(1/w)
I have a huge expression for which the numerators are a big mess, involving numbers, variables, formal sums and unevaluted function, let's call the numerators Ai, with i=1,2,...n
This "beast"...
- 1
0
votes
0
answers
68
views
How can I use a replacement rule as part of a simplification?
I am using Mathematica to symbolically calculate the likelihood for a simple linear regression model. As part of this I want to substitute
...
user57885
0
votes
2
answers
60
views
Replace small expressions in larger expressions?
How can I replace small expressions in larger expressions?
Simple example
Replace[a^2 + b^2 + 2*a*b + x, (a + b)^2 -> c]
I want to get ...
- 593
2
votes
1
answer
72
views
How to get the result in terms of a previously defined expression?
Say I have a vector
X[n_] := Table[Subscript[x, i], {i, 1, n}]
and a matrix of connections:
...
- 214
1
vote
2
answers
72
views
Substituting values from an association thread into a table of expressions
I have asked a question here. Yet I am trying to do the same procedure with AssociationThread Suppose I have the following function which is a normal distribution:
<...
- 3,096
5
votes
1
answer
87
views
Substituting elements of lists into an expression
Suppose I have the following lists,
as = {1, 2, 3, 4};
bs = {10, 20, 30, 40};
and the following expression:
...
- 3,096
5
votes
2
answers
306
views
Replace a randomly chosen part of an expression
Given an arbitrary Mathematica expression, how can I choose a random part of the expression and replace it with another symbol of my choosing?
For example, given $a x^3 +2y\cos(x)- \tanh(x^{y+3})/(x^...
- 25.6k
2
votes
1
answer
83
views
Replace a family of coefficients by a function in a sum
I would like to do something very simple, i.e. replace the coefficients in a sum by a function:
c[1] + c[2] + c[3] /. {c[s] -> (s + 1)/(2 (2 s + 1))}
...
- 711
0
votes
0
answers
43
views
Expanding complex expression and replacing variables in the result
When I'm finished expanding my expression I would like the result to be expressed again in terms of the original variables (like α, S1, T1, T2). I've tried replace, ...
- 11
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
139
views
Making substitution to an expressions with a list of numerical data [closed]
Suppose I have an expression similar to this: y=23.23*(h[x]^2)*(D[h[x],x])*(D[h[x],{x,3}])/(13.2+Cos[0.245x]) The actual expression is a lot more complicated, but ...
- 987
4
votes
4
answers
170
views
ReplaceList doesn't apply rules down to subparts
Somewhat related to a previous question, I'm experimenting with ReplaceList to get the list of all possible transformations we can obtain by applying a rule to an expression. But I don't manage to ...
- 1,529
2
votes
0
answers
140
views
General rule to rewrite function and argument into a new symbol
I am trying to convert Mathematica output into equations I can plug into C. I am presently trying to convert expressions of the form
Derivative[1,0,0][f][t,x,y]
...
1
vote
2
answers
230
views
Suppress arguments in output for pretty print
I would like to define a rule that suppress any arguments of a function for visibility.
I tried:
rule = f_[x__] -> f
While this works well with individual ...
- 1,523