MATLAB R2007a to Mathscript

[DCT]

Hi

I have written MATLAB code to produce a squarewave at a certain frequency for 0.01 seconds. The code then loops back to produce a similar squarewave but at a different frequency, and then concatenates it to the end of the first squarewave. There are 100 such iterations such that it builds a squarewave of changing frequency that runs for 1 second (i.e. 0.01*100). I want to output this squarewave to the computer speakers.

The code works in MATLAB but when i copy it into the Matchscript window it does not. The commands that i am using seem to be compatible with Mathscript and it seems that the problem comes in at the for loop stage. My MATLAB code is pasted below and i have attached the LabVIEW VI with my Mathscript window. Could someone please have a look at my code and see if i am missing any common issues? I am a new LabVIEW user and am not entirely familiar with its intricacies.

______________________________________________________________________________

clc
sampleRate = 40000;
step = 1/sampleRate;


freqArray = [5247.819345    2691.190023    2379.575143    2242.862777    2162.605492    2105.101801    2056.973700    2011.841157    1966.260707    1918.191205    1866.327910    1809.784986    1747.934921    1680.325561    1606.638751    1526.672983    1440.340700    1347.674817    1248.840788    1144.151306    1034.080952    919.278207    800.572260    678.972385    629.941608    670.923135    706.090004    733.248856    750.729600    757.468401    753.055128    737.746864    712.449234    678.666661    638.422079    594.147026    548.544635    504.430794    464.562051    431.461673    407.256955    393.540721    391.268089    400.696344    421.371792    452.163428    479.456733    499.635983    519.683091    539.345489    558.379030    576.550816    593.641724    609.448655    623.786494    636.489853    647.414604    656.439263    663.466274    668.423222    671.264030    671.970137    670.551695    667.048751    661.532385    654.105760    660.331784    659.175196    658.042926    656.973398    656.008980    655.196461    654.587596    654.239768    654.216768    654.589753    655.438402    656.852357    658.933014    661.795790    665.573014    670.417674    676.508334    684.055673    693.311331    704.580088    718.236954    734.751698    754.724945    778.942900    808.463177    844.755078    889.940437    947.233277    1021.807261    1122.692006    1267.554308    1497.662150    1946.857495    4694.713066];
z = [ ];
t2 = [ ];
for n = 0:99
    t = (0 + (0.01*n)) : step : (0.01*(n+1))-step;
    y = (square(2*pi*freqArray(n+1)*t)+1)/2;    % create squarewaves at different frquencies
    z = [z,y];                                  % concatenate y arrays
    t2 = [t2,t];                                % concatenate time arrays
end

plot(t2,z)
sound(z,40000,16)

_______________________________________________________________________________

[DCT]

Btw, I am using LabVIEW 8.2...

[CMal · Accepted solution]

DCT,

Remember that array indices in MathScript are 1-based, so changing the for loop statement to "for n = 1:100" should make it work.  This can be a little confusing because array indices are 0-based in native LabVIEW, so you need to make sure to add or subtract 1 when going back and forth between LabVIEW code and MathScript code.

Chris M 

[DCT]

Thank you! Problem solved 🙂