Output Management

Hi!

I am asking matlab to do this:

      iP = 0; % this is a cell in the dark
      iSat = 1e-8;
      rS = .5; 
      rSh = 300;
      n = 20000; 
      subTotal = solve('iP - iSat * (exp(38.66976*(x+dcellCurrent(1)*rS)/n)-1) -(dcellCurrent(1)*rS + x)/rSh - dcellCurrent(1) = 0',x)

So, I have asked it to print the value of x and store the value of x in subTotal, yes?

But when it prints, it says:

subTotal =

iP*rSh - 1.0*rSh*dcellCurrent(1) - 1.0*rS*dcellCurrent(1) + iSat*rSh - 0.025860000165504001059225606779044*n*lambertw(0, (120843*iSat*rSh*exp((120843*rS*dcellCurrent(1))/(3125*n))*exp((120843*rSh*(iP + iSat - dcellCurrent(1) - (rS*dcellCurrent(1))/rSh))/(3125*n)))/(3125*n))

All I want it to print is the number, not the constants and such.

How do I go about changing the output from an expression to a simple number?

[Oleg Komarov]

what's dcellCurrent?

Answer 1

[Walter Roberson]

Leave out the '' around the expression, and leave out the = 0

subTotal = solve(iP - iSat * (exp(38.66976*(x+dcellCurrent(1)*rS)/n)-1)   -(dcellCurrent(1)*rS + x)/rSh - dcellCurrent(1), x);

[mkeehan]

After doing so, it says:

Warning: List of equations is empty.

> In solve at 70

In transcendentalTesting at 19

??? Error using ==> mupadmex

Error in MuPAD command: Either base or exponent must be a scalar.

Error in ==> sym.sym>sym.mpower at 207

B = mupadmex('symobj::mpower',A.s,p.s);

Error in ==> transcendentalTesting at 19

subtotal = (solve(iP - iSat * (exp(38.66976*(x+dcellCurrent(1)*rS)/n)-1) -(dcellCurrent(1)*rS + x)/rSh -

dcellCurrent(1),x)-dcellVoltage(1))^2 ;

Comments?

[Walter Roberson]

Make sure you

syms x

before executing the solve.

double() around the solve() call, and use .^2 instead of ^2