Cant call function in script, function has switch case

So here is my function, Im trying to do a switch case for a certain n-value

function [wi,na] =  weight_natural(n_poly)
switch (n_poly)
case n_poly==1;
    wi=2;
    na=0;
case n_poly==2;
    wi(1)=1;
    wi(2)=1;
    na(1)=-0.577350269190;
    na(2)=0.577350269190;
case n_poly==3;
    wi(1)=(5/9);
    wi(2)=(8/9);
    wi(3)=(5/9);
    na(1)=-0.774596669241;
    na(2)=0;
    na(3)=0.774596669241;
case n_poly==4;
    wi(1)=0.347854845137;
    wi(2)=0.652145154863;
    wi(3)=0.652145154863;
    wi(4)=0.347854845137;
    na(1)=-0.861136311594;
    na(2)=-0.339981043585;
    na(3)=-na(2);
    na(4)=-na(1);
case n_poly==5;
    wi(1)=0.236926885056;
    wi(2)=0.478628670499;
    wi(3)=0.568888888889;
    wi(4)=wi(2);
    wi(5)=wi(1);
    na(1)= -0.906179845939;
    na(2)= -0.538469310106;
    na(3)= 0;
    na(4)=-na(2);
    na(5)-na(1);
end
end

My main script

clc 
clear all
format short G
%Project one
read=dlmread('data.txt');

number_pts=read(1,1);% read total number of elements
starting_pt=read(1,2);% read starting global point
length=read(1,3);% total length of element
x_dist=read(2,:);% total element length
Ci=read(3,:);% coefficients 
nodes=number_pts + 1;% number of node, between elements
n_poly = 3 ; 
[wi,na] = weight_natural(n_poly)
j=1;
    for k = -5: x_dist
        x_value(1,j) = (((starting_pt + x_dist(j)))/2) + (((starting_pt - x_dist(j)))/2)*wi
        j = j + 1;
    end

Answer 1

[Steven Lord]

Eliminate the "n_poly==" part of your case statements. MATLAB will perform the equality testing for you. See the "Compare Single Values" example on the documentation page for the switch keyword and use it as a model.

[Walter Roberson]

This is the better solution. However, another potential solution is to change the

switch (n_poly)

to

    switch true

and leave all of the n_poly== where they are.

switch true is obscure but legal. I do not recommend it, but it is possible.