How do I make a three-dimensional plot correctly in Scilab?

Question

I am trying to make a plot of three column vectors right now in order to make a three dimensional surface plot, but the output is just a discontinuous line. Any help is appreciated, code is below. Apologies in advance for the confusing variable names.

co = 29;              
BF = .0446;  
WPW = 50;     
E = [0:0.01:2];  //sets up a column vector  
p = [];  
WBR =[];  
w = [];  
t = 8.64E13;  
delta = [0:0.5:100];  
R =[];  
DeltaMu = [];  
Total = [];  

//begin program iteration through k; change "k" value in for loop to change
//the number of iterations the program runs over, and thus the amount
//of degrees of freedom

k = 200;  
for i = 1:k,  

I = 12.5 + 0.167*i;         
mu = I/co;        
sigma = .11*mu;            

cdf = cdfnor("PQ", E, mu*ones(E), sigma*ones(E));  

n = 201;                          // variable over which the loop is iterated    
pdf = zeros(201,1);            // sets up an appendable matrix of all zeros    

temp = 0;                      //initiates a temporary integer variable   
while n > 1,  
    temp = cdf(n) - cdf(n-1); //assigns a value to the temp variable every pass  
    pdf(n) = temp;         //assigns the temp value to the nth slot in the   
                            //column vector, works through the matrix backwards  
    n = n-1;                //iterates the while loop on n  
end                        //breaks from while loop after n hits 1  

temp = cdf(n);  
pdf(n) = temp;  

n = 201;  
while n > 1,  
    a = exp(-WPW*exp(-delta(n)*(1-E)));   
    n = n-1;  
end  

n = 201;                           // variable over which the loop is iterated  
prob = zeros(201,1);             // sets up an appendable matrix of all zeros  
temp = 0;                       //initiates a temporary integer variable   
while n > 1,  
    temp = a(n)*pdf(n);       //assigns a value to the temp variable every pass  
    prob(n) = temp;          //assigns the temp value to the nth slot in the   
                            //column vector, works through the matrix backwards  
    n = n-1;                //iterates the while loop on n
end                        //breaks from while loop after n hits 1

WBR(i) = sum(prob)*BF     
w(i) = mu                      
end

//begin program iteration through k; change "k" value in for loop to change
//the number of iterations the program runs over, and thus the amount
//of degrees of freedom

k = 200;
for i = 1:k,

mu = .5*i;               
sigma = .1*mu;         

cdf = cdfnor("PQ", delta, mu*ones(delta), sigma*ones(delta));  

n = 201;                          // variable over which the loop is iterated  
pdf = zeros(201,1);            // sets up an appendable matrix of all zeros  
temp = 0;                      //initiates a temporary integer variable   
while n > 1,  
    temp = cdf(n) - cdf(n-1); //assigns a value to the temp variable every pass  
    pdf(n) = temp;         //assigns the temp value to the nth slot in the   
                            //column vector, works through the matrix backwards  
    n = n-1;                //iterates the while loop on n  
end                        //breaks from while loop after n hits 1  

temp = cdf(n);  

p = 1-(exp(-t*exp(-delta)));    

n = 201;                           // variable over which the loop is iterated  
Psw = zeros(201,1);             // sets up an appendable matrix of all zeros  
temp = 0;                       //initiates a temporary integer variable   
while n > 1,  
    temp = p(n)*pdf(n);       //assigns a value to the temp variable every pass  
    Psw(n) = temp;          //assigns the temp value to the nth slot in the   
                            //column vector, works through the matrix backwards  
    n = n-1;                //iterates the while loop on n  
end                        //breaks from while loop after n hits 1  

R(i) = sum(Psw)     
DeltaMu(i) = mu                        

end  

n = 200;  
while n > 1,  
    Total(n) =  WBR(n) + R(n);  
    n = n-1;  
end  

xdel(winsid());                          //close any open graphs  
plot3d(WBR, R, Total)     

Answer 1

To plot a surface with plot3d, you need:

• a vector of x-values
• a vector of y-values
• a matrix of z-values, where the (i,j) entry will determine the height over the point (x(i),y(j))

Toy example:

plot3d([1 2 3], [2 3 4], [0 1 2; 2 3 2; 0 2 1])

There is no mathematically reasonable to make a surface plot from three column vectors. What you could do with them is draw a parametric curve, which uses three vectors for x,y,z coordinates:

param3d(WBR, R, Total)   

With your data, the result is still unspectacular because of the high dynamic range with the arrays. Consider plotting on the logarithmic scale.