# (i) x-and-y scales defined as "log", or (ii) calculate the log of variables, or (iii) loglog

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Sim 2023-5-9

Are these three methods (and the corresponding plots) equivalent ways to perform the same task ?
% Method 1
figure
axes('XScale', 'log', 'YScale', 'log')
plot(1:10, 1:10)
title('plot(1:10, 1:10), with both x-and-y scales defined as "log"') % Method 2
figure
plot(log(1:10), log(1:10))
title('plot(log(1:10), log(1:10))') % Method 3
figure
loglog(1:10, 1:10)
title('loglog(1:10, 1:10)') ### 采纳的回答

VBBV 2023-5-9
% Method 1
figure
plot(1:10, 1:10)
ax = gca;
% put this after plot call and use as below
set(ax,'XScale', 'log', 'YScale', 'log')
title('plot(1:10, 1:10), with both x-and-y scales defined as "log"') % Method 2 -->>>> Linear scale but log values of inputs
figure
plot(log(1:10), log(1:10))
title('plot(log(1:10), log(1:10))') % Method 3
figure
loglog(1:10, 1:10)
title('loglog(1:10, 1:10)') ##### 1 个评论显示 -1更早的评论隐藏 -1更早的评论
VBBV 2023-5-9

Method 1 and Method 3 are equivalent but Method 2 is not same as remaining two methods, since Method 2 plots the logarithm of input values on linear scale , while Method 1 uses log scale for plotting linear values, and Method 3 also does same

### 更多回答（1 个）

No,
Method 1 and 3 are equivalent. The X and Y values range from 1 to 10, it does not matter which scale you use, the values remain the same.
% Method 1
subplot(1,3,1)
plot(1:10, 1:10)
title('plot(1:10, 1:10), with both x-and-y scales defined as "log"')
ax=gca;
ax.XScale= 'log'; ax.YScale = 'log';
title('Method 1')
% Method 3
subplot(1,3,3)
loglog(1:10, 1:10)
title('Method 3')
However, in Method 2 the X, Y values change from 0 to 2.3...
% Method 2
subplot(1,3,2)
plot(log(1:10), log(1:10))
title('Method 2') ##### 1 个评论显示 -1更早的评论隐藏 -1更早的评论
Sim 2023-5-12
Thanks a lot both @VBBV and @Antoni Garcia-Herreros for your nice answers! PLease bear in mind that I would accept both of them if I could! :-)

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