logspace equivalent and sin(x) [solved]
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Hello, I have to solve a couple of exercises; the first one asks me to write with ":" the equivalents of this:
x=linspace(0, 10, 5);
x=linspace(-5, 5);
x=logspace(1, 3, 3);
x=logspace(1, 3, 5);
I solved the first by myself ( x=[0:2.5:10] ) because it's easy, but I really can't understand the others; actually I don't just want to solve the exercises but I want to understand if there is actually a method and how it is done.
Second one is this: A = {sin(x), x=1,2, ,1000}, I have to find how many elements of A are bigger than 1/2 using function SUM; actually I don't know that writing, I just started using Matlab, but even Matlab gives me an error, so maybe I thought it was wrong written; any guesses?
采纳的回答
Stephan
2019-11-10
x = 10.^(1:3) % x=logspace(1, 3, 3)
result = sum(A>0.5) % Number of elements in A bigger than 0.5
更多回答（2 个）
JESUS DAVID ARIZA ROYETH
2019-11-10
a=1;
b=3;
c=3;
logspace(a, b, c)==10.^(1:(b-a)/(c-1):b) %are equivalent
on the other hand
x=1:1000;
A=sin(x);
total=sum(A>1/2)
Giacomo Lorenzi
2019-11-10
0 个投票
1 个评论
Steven Lord
2019-11-11
You could "cheat" a little and look at what logspace does.
type logspace.m
I'm using type rather than edit to avoid accidentally modifying logspace. It's short enough that this won't display too much in the Command Window.
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