Hi, I'm really rather new to Matlab, and totally confused. I'm trying to write some equations for evapotranspiration, and I'm rather stuck. I've got my constants and my equations written as below:
gs = 0.108; %stomatal conductance m^-1%
ga = 0.002; %atmospheric conductance m^-1%
G = 0; %soil heat flux W m^-2)%
rho = 1.22; %density of air Kg m^-3%
cp = 1006; %specific heat of air J Kg^-1 degrees C^-1%
gamma = 0.655; %psychrometric constant%
pw = 998; %density of water KG m^-3%
lambda = 2495000; %latent heat for vapourisation J/kg%
Dry = -100 : 100; %Dry Bulb temperature degree C%
sat = 0.611 * exp ((17.27 * Dry)/... %Saturated vapour pressure KPa% 237.3 + Dry); delta = 4098 * sat / ...%slope of vapour pressure curve at air temperature%
(237.3 + Dry)*(237.3 + Dry);Rs = 0 : 40000; %Incoming Radiation W m^-2%
Wet = -100 : 100; %Wet Bulb temperature degree C%
Rn = -18.308 + 0.681 * Rs; %Net radiation W M^2%
Unsat = 0.611 * exp ((17.27 * Wet) /... %Unsaturated vapour pressure KPa% (237.3 + Wet)); Vap = Dry - Wet; % Vapour Pressure Deficit KPa%
Soil = Rn * 0.2; % Soil heat flux%
E= (delta * (Rn - Soil) + (rho * cp * Vap * ga)... / (delta + lambda * (1 +(ga/gs))))Hours = 1:1:23; % Hours in a day%
Secs = Hours * 3600; %seconds in an hour%
Evap = (E/ (lambda * pw)) * 1000 * Secs %Evapotranspiration (mm per day)
My problem however is now that I want to be able to enter my 4 variables, Dry, Rs, Wet and Hours, and solve the equations, but I don't really know how to do it.
I eventually hope to make it into a GUI but I'm just trying to take it one step at a time. Any pointers would be much welcome.
Thanks
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