## 4550 Reputation

9 years, 130 days

## Sample from a distribution fitted to som...

Maple

I have a small data sample of some occurrence in time.  For an example lets take the time it takes kids to finish their lunch to determine wether a school has given them enough time for recess.

The times are (20,15,12,18,15,13,13,10,14,14,15,17,8,22,16) in minutes.

What distribution should I use?

Should I just calculate the mean and std. dev. from the data and generate a normal distribution, like below?
with(Statistics):
a:=[20,15,12,18,15,13,13,10,14,14,15,17,8,22,16]:
m:=Mean(a):
d:=StandardDeviation(a):
X:=RandomVariable(Normal(m,d)):

Sample(X,3) # generate a few samples

I could also randomly choose from the observed 15 data points.

combinat[randcomb](a,3) # randomly pick 3 of data points

Which method would be better?  Is randcomb following any kind of distribution?

## Anaglyph or stereo image...

Maple

Here's something neat to be done in Maple.
This anaglyph or stereo image uses the red green glasses to make the model appear more 3 dimensional.  The static-non-stereo image of the animated plot below is done in maple by plot3d(sin(x*y)^2,x=-2..2,y=-2..2,scaling=constrained)

Anyone?

## javaw can cause maple to crash if output...

Maple

It seems if for some reason Maple runs a command that returns an error but the error is outputing to the display, and it is very very large, javaw.exe will consume enormous amounts of memory and pretty much freeze your system.  It took me forever to get into task manager on Windows to try to kill the processes slowing my system down to a crawl.

For example if you run say listplot on a 60,000 set data element which is not in the correct form for listplot, Maple will error each element and attempt to output it to the screen which on my system quickly ran javaw.exe up to 2.5 Gb of memory usage. But then it went to zero again (probably due to garbage collection or something) and quickly ramped back up into 2 Gb.  Momentarily I was given enough system control to kill some processes to Maple and Firefox which eventually allowed me to take back control of my system.  When this first occurred, I did a hard reset, the second time I wanted to see if I could have any luck otherwise, but it took 5 minutes of frustration to get my system back to normal operating condition.

Hopefully Maple developers can use this information to prevent system hangs like this in the future.  Additionally pushing the interupt the current operation did little to stop the process already underway.

## How to pull the number and type of opera...

Maple

I think I've seen this somewhere in Mapleprimes but I can't locate it. How do you pull the type and number of operations from an equation?

a:=3*x^3-5*x^2+3*y

" *,^,-,*,^,+,* "

## Can this be done in Maple - remove noise...

Can someone show how this can be done in Maple?  I've added the zipped original noisy image .Fig0240(a)(apollo_17_boulder_noisy).zip

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