how to initialize an array in C with undetermined size using C nodes ?

[emnajaoua]

I have been trying to implement an algorithm in C node but i need to initilaize an array which is my output of the c node.

i have tried the traditional way of C coding to initialize the array but errors seem to appear.

[emnajaoua]

or may be if it is not possible to initialize an array is it possible to plot my output pde_sim ?????

[FinchTrain]

Hi,

I have a few questions/comments for you.

Could you describe the errors that you are seeing?

It appears that you do not have an input for the 'z' terminal of your C node. This is contributing to your error as indicated by the red triangle with an exclamation mark in it. Why is it uninitialized?

The link below details outputting data from a C node. It appears that you should be able to output a one dimensional array.

http://www.ni.com/documentation/en/labview-comms/1.0/c-prog/c-node-data-types/

Let me know what errors you have received as well as why the 'z' input is uninitialized.

Regards,

Finch Train

[emnajaoua]

Hi,

The problem is not related to z.the problem is I have the output pde_sim and I want to initialiaze it because it is underlined with red at the end of the script

[FinchTrain]

Hi,

Can you wire a constant into z and then hover over the pde_sim[i] to see what error you recieve? Any more information you can provide regarding the error will be useful. Thanks.

Regards,

Finch Train

[emnajaoua]

Hi,

Thank you for your advice but I have dropped that solution because I need the inverse erf function (inverse Q function)  and not the erfc function.

So I have decided to make a different VI for the inverse Q function but again I am facing problems.

this is the VI that I am trying to do.

I have been copying it scheme from a VI that I have found in NI forums.

Can you help me resolve this issue please.

Thanks,

[FinchTrain]

Hi,

Can you please describe the issues you are seeing on your end? What specific error codes or issues do you see? Could you also link the forum where you found the scheme that you are basing this off of?

Regards,

Finch Train

[emnajaoua]

Hi,

I found the solution in another forum : http://forums.ni.com/t5/LabVIEW-MathScript-RT-Module/erf-function-inputs-not-clear/m-p/3307086#M1910

My problem was how to difne the erf function in the C or M node because it is not a function in the labview communications design.