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Nov
15
answered Integral of Lorentzian yields different results depending on when parameter assigments are made
Nov
15
revised Why does this integral have a complex component?
added 147 characters in body
Nov
15
answered Why does this integral have a complex component?
Nov
14
comment Calculate the covariance of a large matrix
How did you estimate it will takes 10 days per matrix? (btw, 10 days using which type of computer? since the CPU type and amount of RAM should make some difference)
Nov
14
comment Linear Stability Analysis Routine. Normal Modes in NDSolve
In your function eqn1[] and eqn2[], here is an random example from google search mathematica.stackexchange.com/questions/34945/… again, this is something to try, I am not saying it will solve the problem, since I do not know what the problem is :)
Nov
14
comment Linear Stability Analysis Routine. Normal Modes in NDSolve
Just a wild guess, try to add ?NumberQ to the definitions of all the functions arguments for functions called/used by NDsolve. (can't follow your code and try it, since no MWE provided).
Nov
14
reviewed Approve suggested edit on Solving recurrence relationship using iteration
Nov
14
comment Solving recurrence relationship using iteration
Are you saying that input at time i depends on input at time i+1 ?? Normal recurrence is where future values depends on past values, this way the system can be initialized correctly.
Nov
14
answered Add a letter to a variable name from a list
Nov
14
answered Pattern matching in nested lists
Nov
14
revised Fourier-Analysis How to display every period correctly?
deleted 38 characters in body
Nov
14
answered Fourier-Analysis How to display every period correctly?
Nov
13
comment Solving a system of nonlinear equations?
Are you saying all this hard work to come up with some solution and I was using bad equations to start with? oh well....next time I'll avoid Chemistry questions ;)
Nov
13
answered Solving a system of nonlinear equations?
Nov
13
comment Solving a system of nonlinear equations?
You have 7 equations, but I keep counting only 6 variables. If you get rid of one equation, it will help.
Nov
12
comment Numerically solving a system of PDEs where one function is composed with the other
DO you have a reference or published examples of such PDE's? (I mean of similar form) to give one an idea of how they can come about.
Nov
12
comment Numerically solving a system of PDEs where one function is composed with the other
... NDSolve::cdelay: The method currently implemented for delay differential equations does not support delays that depend directly on the time variable or dependent variables. so if the same system is not valid to be solved analytically (mathematically speaking), how could it becomes valid to be solved Numerically? (I'd have to ask my teacher when I go to school tomorrow on this and see what he says about this).. either way, what you are to do does not seem to be supported by direct use of NDSolve...
Nov
12
comment Numerically solving a system of PDEs where one function is composed with the other
I do not think the error message is right. I think the pde itself is not valid mathematically speaking. You have a dependent variable being treated as independent variable. One can see this more clearly in this example: Clear[u, v, x]; eq1 = u'[x] == u[x] - v[x]; eq2 = v'[x] == u[v[x]]; DSolve[{eq1, eq2}, {u[x], v[x]}, x] the error is DSolve::nestdv: "The expression v[x] has nested dependent variables". Now switch to NDSolve, same system, and now you get the delay error: NDSolve[{eq1, eq2, u[0] == 0, v[0] == 0}, {u[x], v[x]}, {x, 0, 1}] and the error is ...
Nov
11
answered NDSolve - 2nd order ODE - how to solve for y and y'
Nov
11
answered Find a notebook I had open recently