Save Sym data per variable

Hello, I have a code which deals with symbolic variables and I have as output a vector whose dimension is known but variable.

The output is symbolic, for example a=[y_1/3+y_2/5 y_1/10+y_2/37]

I would like to save in an ASCII file, not binary, the output and for each row have one element of the vector. The tricky part is the saving in a file, I can do it only in bin, since when I type -ASCII it doesn't do it.

Here I attach a piece of code useful to understand. Thanks for your time.

Antonio

syms a b c x;
results=solve('a*x^2 + b*x + c');
save results.dat results

My output comes as:

results=[-(b + (b^2 - 4*a*c)^(1/2))/(2*a) -(b - (b^2 - 4*a*c)^(1/2))/(2*a)]

Answer 1

[Abhishek Gupta]

One may use DIARY( http://www.mathworks.com/help/releases/R2011b/techdoc/ref/diary.html ) to capture any output to the command window into a text file.

Otherwise, you may convert your symbolic variables into strings and write them into a text file, for instance:

syms a b c x;
results=solve('a*x^2 + b*x + c');
fid = fopen('myfile.txt', 'w');
fwrite(fid, char(results), 'char');
fclose(fid);

Hope this helps.

Abhi...

[mortain Antonio]

Dear Abhi, thanks a lot for your reply.

I wanted to isolate the single equations and the coefficients....I guess I need to work a bit on it, but what you wrote is useful.

Ciao

[Nachum Lerner]

Thanks for the great answer, helped also me.

Nachum

Answer 2

[Walter Roberson]

results = char(solve('a*x^2 + b*x + c'));

[mortain Antonio]

Hello Walter,

thanks for your answer, but this is not what I am looking for.

I want to save

%start code

>> syms a b c x;

>> results=solve('a*x^2 + b*x + c')

results =

-(b + (b^2 - 4*a*c)^(1/2))/(2*a)

-(b - (b^2 - 4*a*c)^(1/2))/(2*a)

save results.dat results

%end code

I want to save in a text file:

-(b + (b^2 - 4*a*c)^(1/2))/(2*a)

-(b - (b^2 - 4*a*c)^(1/2))/(2*a)

I don't know if it is possible.

Using your approach, it saves some numbers:

1.0900000e+002 9.7000000e+001 1.1600000e+002 1.1400000e+002 1.0500000e+002 1.2000000e+002 4.0000000e+001 9.1000000e+001 9.1000000e+001 4.5000000e+001 4.0000000e+001 9.8000000e+001 3.2000000e+001 4.3000000e+001 3.2000000e+001 4.0000000e+001 9.8000000e+001 9.4000000e+001 5.0000000e+001 3.2000000e+001 4.5000000e+001 3.2000000e+001 5.2000000e+001 4.2000000e+001 9.7000000e+001 4.2000000e+001 9.9000000e+001 4.1000000e+001 9.4000000e+001 4.0000000e+001 4.9000000e+001 4.7000000e+001 5.0000000e+001 4.1000000e+001 4.1000000e+001 4.7000000e+001 4.0000000e+001 5.0000000e+001 4.2000000e+001 9.7000000e+001 4.1000000e+001 9.3000000e+001 4.4000000e+001 3.2000000e+001 9.1000000e+001 4.5000000e+001 4.0000000e+001 9.8000000e+001 3.2000000e+001 4.5000000e+001 3.2000000e+001 4.0000000e+001 9.8000000e+001 9.4000000e+001 5.0000000e+001 3.2000000e+001 4.5000000e+001 3.2000000e+001 5.2000000e+001 4.2000000e+001 9.7000000e+001 4.2000000e+001 9.9000000e+001 4.1000000e+001 9.4000000e+001 4.0000000e+001 4.9000000e+001 4.7000000e+001 5.0000000e+001 4.1000000e+001 4.1000000e+001 4.7000000e+001 4.0000000e+001 5.0000000e+001 4.2000000e+001 9.7000000e+001 4.1000000e+001 9.3000000e+001 9.3000000e+001 4.1000000e+001

Thanks again for your reply

Antonio

[Walter Roberson]

This is not something I can test myself, but I can tell you that that output does not look as expected and documented.

[mortain Antonio]

I will try in a different way and see what it happens....

Thanks for your reply, Antonio

Answer 3

[Shahram Alipourazadi]

To isolate each row you can write:

fid = fopen('myfile.txt', 'w');
for i=1:length(results)
fprintf(fid, '%s\n',char(results(i)));
end
fclose(fid);

Generally first you should convert each argument into string and then using string manipulation functions arrange them