# MATLAB: How to plot multivariable functions against each other

MATLABmultivariable function fplot mesh

Have defined to functions based on biological mechanisms and am trying to plot the two against each other (GF on the x-axis, ECM on y-axis) where the variables in the equations (x and y) are the possible concentrations of the molecules which are reactants. The rest of the constants are defined. For some reason I cannot find a way to plot them?
``% Variable Initializationx = linspace(0,10);y = linspace(0,10);% Parametersv2fak = 0.05; v1fak = 0.04; k2fak = 0.1; k1fak = 0.1; fakt = 1;kagf = 0.1; kdap1 = 0.15; vs2ap1 = 0.05; kafak = 0.1; vsap1 = 0.05;GF = [kagf * (kdap1 * x - vs2ap1 * (y / (kafak + y)))] / [vsap1 + vs2ap1 * ...    (y / (kafak + y)) - kdap1 * x];ECM = (v2fak / v1fak) * (y / (k2fak + y)) * (k1fak + (fakt - y)) / ...    (fakt - y) - [kagf * (kdap1 * x - vs2ap1 * (y / (kafak + y)))] / [vsap1 + vs2ap1 * ...    (y / (kafak + y)) - kdap1 * x];plot(GF,ECM);``

#### Best Answer

Vectorize all the vector multiplications and divisions, and it works:
``GF = (kagf * (kdap1 * x - vs2ap1 * (y / (kafak + y)))) ./ (vsap1 + vs2ap1 * ...    (y / (kafak + y)) - kdap1 * x);ECM = (v2fak / v1fak) * (y ./ (k2fak + y)) .* (k1fak + (fakt - y)) ./ ...    (fakt - y) - (kagf * (kdap1 * x - vs2ap1 * (y ./ (kafak + y)))) ./ (vsap1 + vs2ap1 * ...    (y ./ (kafak + y)) - kdap1 * x);``
Also, use parentheses instead of square brackets unless you intend to define matrices with individual elements.