Execute only once

Hi

I wrote a program in Embedded Matlab Function in Simulink. I have to define some variables as 0(zero) at first but they will be 0 only for the beginning. Then these variables are calculated in the program. Is there a way to execute the definatiion commands only once? Thanks in advice...

Answer 1

[Fangjun Jiang]

I guess you want to declare your variable persistent. type doc persistent for example. To initialize, you can do

if ~exist('VarName','var')
VarName=0;
end

[Kaustubha Govind]

The more standard way would be:

persistent VarName;

if isempty(VarName)

VarName = 0;

end

[Fangjun Jiang]

Thank you Kaustubha for pointing it out. Indeed it needs to use isempty(), not to use exist(..,'var') because once the 'persistent VarName' line executes, the variable VarName will exist.

[Coolman]

Could you do this for a figure also so I can make sure someone does not make tons of pop ups by clicking the same button multiple times?

Answer 2

[Clemens]

@Kaustubha:

Thanks a lot for the solution I just came across. By adding these 3 extra lines of code my Embedded Function executes about 100 times faster in simulation ;)