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4h
answered Help with coding triangular nodes/elements
5h
revised Horizontally compress a picture with varying compression ratio
added 177 characters in body
5h
revised Horizontally compress a picture with varying compression ratio
added 144 characters in body
5h
answered Horizontally compress a picture with varying compression ratio
1d
comment Example of Integrate applying a numerical evaluation N
Thats different. The numeric x makes things that depend on x numeric as expected. There is no reason for Integrate to numericize the constant. Anybody thinks this makes sense explain why Integrate[a[1] x , {x, 0, 1.}] leaves the constant alone while Integrate[a[1] + x , {x, 0, 1.}] evidently applies N to it..
1d
comment Export Grayscale Bitmap
confirmed by file size check: FileByteCount[Export["test.bmp",Image[RandomReal[255,{1000,1000}],"Byte"]]]/1.*‌​^6 -> 1.001
1d
comment Export Grayscale Bitmap
In fairness most of the opts are documented only under Import. This one point : " Export creates a BMP file with indexed color [... ] if the ColorMap element is specified. " seems to be just wrong however.
1d
comment Export Grayscale Bitmap
After playing with this a good bit looking at file sizes, the only thing that actually produces a one byte per pixel file is @SimonWoods approach of converting the type to Byte before Export sees it. (That is to say the documented options simply do not work )
2d
awarded  Yearling
2d
comment Example of Integrate applying a numerical evaluation N
I see that, I mean its not obvious that should cause the entire resulting expression to be evaluated numerically.
2d
comment Example of Integrate applying a numerical evaluation N
nice solution, yet it is not obvious why Integrate applies N to the result in the first place.
2d
comment Example of Integrate applying a numerical evaluation N
I also can not reproduce your second example -- what version?
2d
answered Find Root Iteration
2d
comment Find Root Iteration
mysum is not even a function of x in your sample
Aug
19
comment How to plot several functions without jumping? (multiple eigenvalues of a system as functions of 2 parameters)
@altroware fixed that issue i think - verified only with 9 which it turns out has the Indexed function (undocumented).
Aug
19
revised How to plot several functions without jumping? (multiple eigenvalues of a system as functions of 2 parameters)
deleted 13 characters in body
Aug
19
revised How to plot several functions without jumping? (multiple eigenvalues of a system as functions of 2 parameters)
added 316 characters in body
Aug
18
comment Numerically integrating a list-valued function
that issue is somewhat avoided if you do : foo[x_?NumericQ] :=foo[x]= {x^2, x^3} ( though not entirely in case NIntegrate wants to evaluate the expressions at different points )
Aug
18
answered Numerically integrating a list-valued function
Aug
18
comment Numerically integrating a list-valued function
note this is evaluating each of the list expressions twice for each x .. so it illustrates the issue but isn't likely a good approach for performance reasons.