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1h
comment NIntegrate and Sum give different results in summing functions
why would you expect NIntegrate[ .. {R,1,10^16}] to give the same result as Sum[ .. {R,1,1.5,0.001 }] ?
1h
revised NIntegrate and Sum give different results in summing functions
added 129 characters in body
1h
revised Equation simplification
added 59 characters in body
1h
answered Equation simplification
May
22
comment Encapsulated plot function misbehaves
+1 good observation. If you see the polynomial that results from ZernikeR[100, 0, r] you can see why extended precision is needed. Actually you can see the trouble if you just do (z = ZernikeR[100, 0, r]; z /. r -> .9) vs ZernikeR[100, 0, .9]
May
22
answered Numerical integral speed
May
22
comment Numerical integral speed
Wrap NDSolveValue in Module : Module[{s}, NDSolveValue[] ] if you really must re-use the same symbol as the ode independent variable as you use elsewhere.
May
22
comment Numerical integral speed
you can actually remove all of the delayed definitions except for der. Change the s in the NDSolveValue expression to something else, so it doesnt get confused by your later unrleated assignment of s for some other purpose.
May
22
awarded  Nice Answer
May
21
comment Binary file gymnastics
Be aware fortran can very well write an arbitrary mix of types within a block. It can be near impossible to reverse engineer if you don't know what you are looking for.
May
21
comment Problem using NDSolveValue
Is this some physical problem? Start there and develop boundary conditions that make sense.
May
21
comment Problem using NDSolveValue
your condition u[t, 302] == 0.21 says u=.21 for all t and r=302. (The analytic solution satisfies that, although it rises so sharply at the edge Plot3D doesn't show it very well )
May
20
answered Problem using NDSolveValue
May
20
comment Plotting a numerical integration
posted code does not work. Do you really want all those definitions delayed ( you are reevaluating NDSolveValue every time you reference c1 )
May
20
comment Handling *.in and *.out files
is this about simple import, or pipes? do you want to run from comand line? suggest you reword to clarify what you are asking. question title makes no sense..
May
20
revised Interact with external program
added 16 characters in body
May
18
answered Can this be written well, without loops?
May
17
awarded  Good Answer
May
8
comment Importing large data without using Import
use <code> .. </code> instead of back ticks..
May
8
answered Question about a catalytic equality?