What do this expression mean '/\\\\r\n2' in symbolic integration?

I did a symbolic integration for the limit of variables defined as (f(eta,w),eta, etamin, etamax,w, wmin,wmax) and obtained the result.

result(eta,w)=int(int(- 25*abs(sin(eta))*((25*abs(cos(w))*sign(cos(eta))^2*sign(cos(w))*sin(eta) + 50*abs(cos(eta))*dirac(cos(eta))*abs(cos(w))*sign(cos(w))*sin(eta))*(25*abs(cos(eta))*sign(cos(eta))*sign(sin(w))^2*cos(w) + 50*abs(cos(eta))*sign(cos(eta))*abs(sin(w))*dirac(sin(w))*cos(w)) + (25*sign(cos(eta))^2*abs(sin(w))*sign(sin(w))*sin(eta) + 50*abs(cos(eta))*dirac(cos(eta))*abs(sin(w))*sign(sin(w))*sin(eta))*(25*abs(cos(eta))*sign(cos(eta))*sign(cos(w))^2*sin(w) + 50*abs(cos(eta))*abs(cos(w))*sign(cos(eta))*dirac(cos(w))*sin(w))) - 25*abs(cos(eta))*abs(cos(w))*(25*sign(sin(eta))^2*cos(eta) + 50*abs(sin(eta))*dirac(sin(eta))*cos(eta))*(25*abs(cos(eta))*sign(cos(eta))*sign(sin(w))^2*cos(w) + 50*abs(cos(eta))*sign(cos(eta))*abs(sin(w))*dirac(sin(w))*cos(w)) - 25*abs(cos(eta))*abs(sin(w))*(25*sign(sin(eta))^2*cos(eta) + 50*abs(sin(eta))*dirac(sin(eta))*cos(eta))*(25*abs(cos(eta))*sign(cos(eta))*sign(cos(w))^2*sin(w) + 50*abs(cos(eta))*abs(cos(w))*sign(cos(eta))*dirac(cos(w))*sin(w)), w, -pi/2, pi/\\\r\n2), eta, -pi, pi)

When I run this function in a for loop Matlab itself cant recognize the portion in limit

.... w, -pi/2, pi/\\\r\n2), eta, -pi, pi)

What's going on? How to make it correct?

Answer 1

[Walter Roberson]

It means that you are using R2015a (and possibly R2015b, I would need to check again), and that you are using MS Windows.

There was a glitch in the formatting of output around that time. Each \r stands for a carriage return, each \n stands for a linefeed, and each \\ means "continued on next line" . So it happens to get to that point in the output, realizes that the line has gotten pretty long, so it emits "to be continued" carriage-return new-line .

These do not affect the calculations: the calculations are being done with internal expressions that are in binary form. This only affects display of expressions.

You cannot directly get it to remove the extra characters from a symbolic expression because they are not really there.

However, if you char() a symbolic expression for display purposes, you can remove each \\\r\n sequence with strrep() or with

regexprep(S, '\\\\\(\\[rn])+', '')

This replacement is designed to be portable to Mac and Linux as well.

[Hirak]

Thanks a lot. It was truly helpful.