# Matlab help a noob (1 Viewer)

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#### dervast

Hi there.. I am really noob to matlab i want to draw the following equation
P(L)=Po*e^(-aL)
How can i draw this function?
Can u help me?
L takes values from 0 to 10km
a=0.2db/km
and Po=1watt

#### hypnagogue

Staff Emeritus
Gold Member
Well, start with the basics... do you know how to enter your data for L into Matlab? How about P(L)?

Code:
Po = 1; % define Po
a = 0.2; % define a
L = 0:10/100:10 % make a vector L with 100 elements evenly spaced from 0 to 10

%option 1, compute P(L) one element at a time
for i = 1:length(L) %loop through all values of L
P1(i) = Po*exp(-a*L(i));
end

%option 2, compute all the values at once
P2 = Po*exp(-a*L);

figure;plot(L,P1) % Plot P vs L

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