MATLAB by rudra pratap

2.5 Lesson 5: Creating and Executing a Function File
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4. function w = crossprod (u , v) ;
% CROSSPROD : function to compute w u x v for vectors u & v
% call syntax:
% w = crossprod (u,v) ;
% ------------
if length (u) >3 I length (v) >3 % check if u OR v has > 3 element s
end
error ('Ask Euler . This cross product is beyond me .')
w = [u (2) *v (3)-u(3) *v(2) ;
u(3) *v(l)-u(l)*v(3) ;
u(l)*v(2)-u(2)*v(1)] ;
% first element of w
% se cond element of w
% third element of w
Can you modify this function to check for 2-D vectors and set the third component
automatically to zero?
5. function s = gseriessum(r,n) ;
% GSERIESSUM : function to calculate the sum of a geometric series
% The series is 1+r+r-2+r-3+ . . . . r-n (up to nth power) .
% call syntax :
% s = gseriessum(r,n) ;
% ------------
nvector =
O:n;
series = r.-nvector ;
s = sum ( s eries) ;
% create a vector from 0 to n
% create a vector of terms in the series
% sum all elements of the vector 'series' .
6. function [capital ,interest] = compound (capital ,years ,rate ,timescomp) ;
% COMPOUND : function to compute the compounded capital and the interest
% call syntax :
% [capital ,interest] = compound (capital ,years ,rat e ,timescomp ) ;
% ------------
xO = capital ; n = years ; r = rate ; k = timescomp ;
if r>l
% check for common mistake
end
disp('check your interest rate . For 8% enter .08, not 8. ')
capital = xO* (l+r/k) -(k*n) ;
interest = capital - xO ;
[Ans. (i) Quarterly: $346.86, Daily: $349.83, Difference: $2.97.]