# MATLAB Help - Comparing values/Indexing

• nvalia

## Homework Statement

I am very, very new to MATLAB, and can't seem to figure out this seemingly simple problem.

Given a t-array and a y-array for a decaying exponential function, my task is to find the first relative maximum in the graph without using Matlab's preset relative max. functions. I'm attempting to do this by comparing y-values at a certain "t" to y-values at "t0" and "t1" (before and after "t"). I'm using indexing, for loops, etc.

N/A

## The Attempt at a Solution

function[max,t_max] = relMax(t,y)
for i = 1:.001:length(t);
y(:,i+1) = y;
y0 = y(:,i);
y1 = y(:,i+2);
if (y0<y && y>y1)
max = y;
disp(max)
t_max = t;
disp(t)
break
end
end

---

Clearly I am making some kind of stupid mistake here. I don't really know how to use indexing very well, and it's causing me problems.

Last edited:

## Homework Statement

I am very, very new to MATLAB, and can't seem to figure out this seemingly simple problem.

Given a t-array and a y-array for a decaying exponential function, my task is to find the first relative maximum in the graph without using Matlab's preset relative max. functions. I'm attempting to do this by comparing y-values at a certain "t" to y-values at "t0" and "t1" (before and after "t"). I'm using indexing, for loops, etc.

N/A

## The Attempt at a Solution

function[max,t_max] = relMax(t,y)
for i = 1:.001:length(t);
y(:,i+1) = y;
y0 = y(:,i);
y1 = y(:,i+2);
if (y0<y && y>y1)
max = y;
disp(max)
t_max = t;
disp(t)
break
end
end

---

Clearly I am making some kind of stupid mistake here. I don't really know how to use indexing very well, and it's causing me problems.