# User Portlet

Jason Grigsby
Discussions
You have an error using square braces where you should have round braces. The working form is s = NDSolve[{x'[ t] + (6.489*10^-28) ((3.84*10^27) (1 - t) (10^5*(1 - t) - (2*10^5)*x[t] + 1) (10^5*(1 - t)...
This would be easier to respond to if we had some example code. While I would definitely suggest using Piecewise over Which or If, it is unclear whether this is the primary issue you are running into.
I can't seem to copy from more than one cell at a time. However, you can go to the File button and select Download which will let you open the notebook in Mathematica and interact with it normally. If you are ok with one cell at a time, hovering the...
We can look at this in pieces. Let's first examine your code: For[i = 1, i
I'm not entirely sure this answers your question, but here is a very simple example: values = {} Manipulate[Column[{x, Button["Add to values", values = Append[values, x];]}], {x, 0, 5}] Every time the button is hit, the current value of x...
It's hard to know exactly what you are asking for here. I'll make an assumption that you have a list of floating point sets {Sign, Exp, Mantiss}. If so, you could use replacement: In[4]:= fps = {{-1,-4,1.2345},{1,2,9.8765}} Out[4]=...
I am guessing you have a stirng that happens to have the \" character in it. This is unnecesary and won't work. Try the following [mcode]In[6]:= GenomeData["SCNN1A"]//Short Out[6]//Short= CCGGCCAGCGGGCGGGCTCCCCAGCCAGGCCGC\[Ellipsis]...
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So generically, there are a number of tests when examining a PDE problem solved with MoLs. However, the different tests don't address all possible issues.  A common test is to check convergence. For instance, if you  used RK4 and fourth-order finite...
Frank, that was the one I kept trying to come up with but I had some sort of mental block. I eventually settled on just using replacement. I'm glad you figured it out because I was getting really frustrated with myself. I like the other solutions...