Christopher2222

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17 years, 144 days

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These are replies submitted by Christopher2222

Thanks for the replies.

So how would I move the 1 over in this general case

 

 

 

restart

with(Student[Calculus1]):

arc := ArcLength(f(x), x = a .. b)

int(((diff(f(x), x))^2+1)^(1/2), x = a .. b)

(1)

``

 

 

 

 

You could use randcomb to reduce points.

with(combinat):
a:=yourdatalist

randcomb(a,3000)

However I don't know wether it would retain the fit shape or if there's a similar statistics data sampling of 3000 points (-other mapleprimers - is there?)

 

Could create a little procedure, but the funny thing is (as a side issue) it won't simplify the same inside the proc as it would outside.

dint := proc (a, b, c, d)
  simplify(subs(b = d, int(a, b))-subs(b = c, int(a, b))):
end proc:

dint(exp(x^3),x,1,2)


simplify(%)
 
whereas outside of the proc

no second simplify is necessary
 

@vv  you did mention it refuses to compute over 1..2 , which is incorrect.  I merely proved Maple does compute the answer. 

 

Works using numeric
int(exp(x^3), x = 1 .. 2, numeric)
                                                  275.5109838

 

@Carl Love thanks I converted it back to a post so Maplesoft would better notice it and hopefully answer

As far as my records show a Maple 6 search should have brought up 157 applications on the Maplesoft applications search but only brought up 43 applications

 

Using numeric brings up an undefined nasty

Change the order of your variable ranges in your first two examples, and see if they turn out correct. (I'm not around Maple today so I can't check)

 

 

@vv .. whoops yes, a two dimensional probability, sorry I made it out as two combining 1 dimensional probabilities. 

I appologize if the proof is wrong


 

restart; with(Statistics)

with(plots):

a := RandomVariable(Normal(0, 1))

_R

(1)

f := PDF(a, x)

(1/2)*2^(1/2)*exp(-(1/2)*x^2)/Pi^(1/2)

(2)

int(f, x = -infinity .. infinity)

1

(3)

int(f, x = -infinity .. 0)

1/2

(4)

b := RandomVariable(Uniform(-2, 2))

_R0

(5)

g := PDF(b, x)

g := piecewise(x < -2, 0, x < 2, 1/4, 0)

(6)

int(.25, x = -2 .. 0)

.5000000000

(7)

f*g

sqrt(2)*exp(-(1/2)*x^2)*piecewise(x < -2, 0, x < 2, 1/4, 0)/(2*sqrt(Pi))

(8)

int(f*g, x = -2 .. 0)

(1/8)*erf(2^(1/2))

(9)

evalf(%)

.1193124670

(10)

int(f*g, x = -infinity .. 0)

(1/8)*erf(2^(1/2))

(11)

``


 

Download statistics_two_distributions.mw

Probability(X<0) = 0.5
Probability(Y<0) = 0.5

Probability (X*Y<0) = 0.1193124670

 

@vv  The answer you produced is for 4 normal distributions.  And Maple computes that correctly.

If all distributions in Maple were classified as Normal, Maple would arrive at the same answer Mathematica came up with.

 

Alternatively it could suggest that it was user error and Mathematica was actually calculating the CDF of four Normal distributions and not two normal and two uniform distributions.  And in a haste to broadcast the error, the op didn't realize the difference. 

Markiyan, are you sure Mathematica wasn't calculated with four normal distributions?

Maple 2016 offers the same as Maple 12 but you have to tell it


 

Which one is right?  equating the two (mathematica and maple) brings up a fail

Maple 12 outputs

@acer thanks for filling in the missing versions.  I didn't realize I had missed so many.  I was using mapleprimes to search for update release notices as a rough guide.

As for calculating the computed dates, I based it on the month they were released in. 

version number = year + 1/12 * (month released in -1 ) # for some rough positioning in the graph.

 

 

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