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Basic Plot with Log scale of nonlinear function

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Brendon Villegas
Brendon Villegas on 14 May 2012
I am new to matlab so my apologies for struggling with basics. I am plotting the following function:
y=(1.018*10^10)*[x/(1+((8.03*10^8)*x)^2) + (4*x/(1+4*((8.03*10^8)*x)^2))];
Based on the plot function I tried logspace but it gave me this error message:
??? Error using ==> mpower Inputs must be a scalar and a square matrix. To compute elementwise POWER, use POWER (.^) instead.
I tried setting a scale but was unsure how to properly write the log scale in terms of x:range 1:step size:range 2???
This plot is for a contrast agent used in MRI and this specifically is BPP theory. The end of the T1 and T2 plots are divergent while in another regime it is linear. I am trying to plot this on a scale from 10^-9 to 10^-5 and then another plot, preferably on the same plot the Relaxivities which are T1^-1 and T2^-1. For some reason when I plot this graph, the x scale is always -1 to 1.5 and the y-scale is 16.5 to 19??? Even more confusing because I have changed the scale of x but nothing else changes?
Thank you for the help. I was a Mathematica student trying to make the conversion.

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Answers (1)

Honglei Chen
Honglei Chen on 14 May 2012
You probably want to use ./, .*, and .^ instead.

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