Unable to display symbolic expression

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Marius Beul
Marius Beul 2015-7-31
评论： Walter Roberson 2015-8-4
I have a small .mat file attached (29kB), which contains a struct of symbolic expressions. If I want to print or substitute the symbolic expressions, MATLAB freezes. This happens e.g. with Test.t1 My first thought was, that the expressions are to complex/long to display, but how can that be if the .mat is so small?
Marius
MATLAB 8.1 2013a, Symbolic Math Toolbox 5.10

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回答（2 个）

Azzi Abdelmalek
Azzi Abdelmalek 2015-7-31
Try to display the first element of Test.t1
Test.t1(1)
Output truncated. Text exceeds maximum line length of 25 000 characters for Command Window display
The expression is too big in length (not in memory) to be displayed by Matlab
  2 个评论
Steven Lord
Steven Lord 2015-7-31
You may be able to SIMPLIFY the symbolic command or use VPA to approximate rational numbers using a small number of decimal places in order to reduce the length of the symbolic expression.
Marius Beul
Marius Beul 2015-8-4
Simplify takes like forever, but I will manually try to evaluate a subset of the equation and see if some parts of it can be neglected.

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Walter Roberson
Walter Roberson 2015-8-1
You could try this:
tfile = tempname;
feval(symengine, 'write','Text', tfile, Test.t1(1));
t11string = fileread(tfile);
Now you can examine t11string using any convenient method. But it may be large...
  2 个评论
Marius Beul
Marius Beul 2015-8-4
This gives me:
Error using mupadengine/feval (line 157) MuPAD error: Error: Invalid input. 'expression' is expected. [line 1, col 12]
Walter Roberson
Walter Roberson 2015-8-4
Sorry I do not have the toolbox to test with.

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