385 reputation
210
bio website andrewjaffe.net/blog
location London, United Kingdom
age 47
visits member for 1 year, 4 months
seen Feb 18 at 18:39
Astrophysicist, cosmologist, Mac user, blogger, python fan.

Dec
11
awarded  Yearling
Nov
22
comment How can we multiply nested matrices?
How do you have this stored?
Aug
19
comment Mathematica not plotting whole logarithmic function
But are you sure the real part is what you want?...
Aug
6
comment Value for x such that |(x-y)| is minimum
Do you perhaps mean to minimize the sum over the |x-y_i|?
Aug
5
awarded  Critic
Aug
1
answered Plot of a function which includes numerical integrals
Jul
18
answered How can I find all values of $m$ such that my cubic equation has three different positive solutions?
Jul
18
comment How can I find all values of $m$ such that my cubic equation has three different positive solutions?
Why are you taking the derivative of f[x]?
Jun
26
answered Units, plotting and empty plots
Jun
26
comment Units, plotting and empty plots
Well, you've got at least one syntax error (but it doesn't solve the problem): you need {V,Quantity[0.06, "Liters"], Quantity[0.6, "Liters"]} as your plot limits, and you probably also don't want the curly braces around PVW call.
Jun
14
comment Digital filter of image in Fourier space
So why not just do what you suggest yourself? Multiply your fourier domain picture by something which highlights the modes you are interested in, since you know where they are in fourier space.
May
16
comment Write a function that returns the logarithmic derivative
Note that the expressions like func[f_]:=f'/f are not instructions about how to differentiate the particular function f that you've defined as "In:"! That is the definition for the pattern f_ which you just happen to have used the same letter for as your function.
Apr
2
awarded  Enlightened
Apr
2
awarded  Nice Answer
Apr
2
comment How to change the value of an array that is outside the For loop, from inside the For loop
Please put all this in the question! Do you want H to be a function of d? If so, define it that way.
Apr
2
comment How to change the value of an array that is outside the For loop, from inside the For loop
I think we need more information about what you're actually trying to do. When does H change? Inside the Do? Should eigenvect change when that happens? If so, you need to explicitly call Eigensystem each time.
Apr
2
awarded  Commentator
Apr
2
comment How to change the value of an array that is outside the For loop, from inside the For loop
Have you tried that?
Apr
2
comment How to change the value of an array that is outside the For loop, from inside the For loop
Have you tried?
Apr
2
comment How to change the value of an array that is outside the For loop, from inside the For loop
My question/point stands: Do you want eigenvect to be different once you've changed H? If so, you need to put Eigensystem[H] inside the loop (but you don't need to define H itself inside the loop). Or do you just want there to be a new H once you've finished the loop? In that case, you can just alter H itself without calling Eigensystem.