How can I solve This Equation?

I all, I have to solve thise equation VFA=408.5 +25.4 pH + 33.9 COD/N -1.8 pH x COD/N +1.8 pH2 -0.3 COD/N2

where pH is a column vector and COD/N is a row vector (10000 numbers).

the result should be a matrix...

Thanks for the help!!

Answer 1

[Walter Roberson]

Use ndgrid() or meshgrid() and vectorize your expressions. You will need to figure out what pH2 and N2 are, though.

[mirko d'antoni]

Hi, thanks for your answer. Basically I want built a matrix using the equation reported previously. The problem is that pH is a column vector and COD/N is a row vector... so I can't do the sum. I don't now how solve this problem. I tried to use meshgrid()but doesn't works.

[Torsten]

Use pH and transpose(COD/N).

Best wishes

Torsten.

[mirko d'antoni]

Sorry, maybe I have not explained well.. the results that I want is this one.. Thanks

[mirko d'antoni]

calculate each cell.. apply this equation in each cell in function of corresponding pH and COD/N values.

[mirko d'antoni]

Yessss thanks for the huge help!!!

[Walter Roberson]

[gpH, gCODN] = ndgrid(pH, COD/n);

VFA = 408.5 + 25.4 * gpH + 33.9 * gCODN - 1.8 * gpH .* gCODN + 1.8 * gpH.^2 - 0.3 * gCODN.^2;

Note: I have interpreted COD/N2 here as (COD/N)^2 . If it was intended to be COD/(N^2) then the above code is not correct.