## why do i get inconsistent plot with the same expre...

hi, learners of maple like me, i was handling a project,but i came across this problem,and i began to doubt the accuracy of maple-plot,,,

very simply expression,result3,changing with the parameter f,

i first plot the f from 100 to 5000,

than i need to watch closer,

so i change the define domain of parameter f, plot f from 100 to 1000,

and the result of plot definitely  differs from the previous one.

low vally in the first figure (f in the scale of 100-1000),disappears! that's insane...

you can see below,

anyone see it, can you give me some clue? i really do not understand this. why ,why why,,

 (1)

## Numerical solution of a function...

Hi,

This is regarding numerical solution of a function and plot. I have a function in the form of , and i need to plot it with omega (as the expression is too long i cant insert it here). Now, if i am changing the range of omega in plot command then I am getting different plots for the small values of omega. Let's say if i change the range from 1..10 to 1..50 and look at the plot in the range of 1..3 then the plots looks different. Apart from this if i change the value of Digits  from 10 to 30 or 40 then every time i am getting an entire different  plot. As the expression if too long i cant convert it to Matlab expression and plot there. How to fix these issues. Please help me regarding this.

Regarding

Sunit

## How to increase accuracy?...

Another_way_to_calculate_the_definite_integral.mw

ptin the file I upload is a complicated expression containing θ and r. Will the accuracy of the result be affected if I use the second method in the file to calculate the definite integral?

## Plot of function in prescribed interval?...

Dear all,

I have the function

y:=x->-9.8455282400*10^9142*exp(-(2/3)*x^(3/2))/(x^(1/4)*sqrt(Pi))+3.3889331940*10^(-9169)*exp((2/3)*x^(3/2))/(x^(1/4)*sqrt(Pi))+(16/153)*x^(7/6)*sqrt(Pi)*exp((2/3)*x^(3/2))+Pi*((1/2)*exp(-(2/3)*x^(3/2))*(-1+exp((2/3)*x^(2/3)))/(x^(1/4)*Pi)-(16/153)*x^(7/6)*exp((2/3)*x^(3/2))/sqrt(Pi));

how can I plot y versus x with x in the interval (1000, 1001).

First, it's simple to verify that y(1000)=0; y(1001)=1;  So (1000, 0) and (1001,1)  belong to our graph.

I tried plot( y, x=1000..1001); but there is no curves.

Thank you in advance to help me to plot the graph of this function.

with brest regards,

## Processor usage in massive computation...

I have a pair of markov matrices that are 250x250 and 500x500 in size. I am raising these matrices to high powers, like 10^17 by 10^12. (I'm using a do loop.) If I set digits:=15, Maple will use 100% of the processor that is available. If I set digits:=16+ Maple will only use 1 thread of my processor. Why? It is the same matrix same program. The only thing that changes is the digits of accuracy. This seems exactly backwards from what it should be. As a result, my AMD9590 processor will run full blast when I choose 15 digits of accuracy and gets the biggest matrix done in 1-2 hours. If i set the accuracy to 17 digits, it takes half a day or more to do the same thing!!! 2 digits of greater accuracy should not take an additional 20 hours!

Thanks

## inconsistent results in maple 12 and maple 15...

sign is different runnning the same script in maple 12 and maple 15 in different machine, just using matrixmultiply and matrix(xxx, shape=hermitian)

assume my window 7 infected by virus, can maple prevent virus change

its accuracy?

or

is there any change between maple 12 and maple 15?

i feel that i will have to make large effort in order to find reason such as reinstall maple 12.

window 7 maple 15

[[a = 3.720799777 10 , b = -3.720817167 10 ]], 0.3469023622
[(-0.737729376724384 + 0. I) ((-0.737729376724384100 + 0. I) a

+ (-0.738311510115612690 + 0. I) b) + (-0.590656319609631

- 0. I) ((-0.590656319609630831 + 0. I) a

+ (-0.589459378339369122 + 0. I) b) + (0.326925800179577

- 0. I) ((0.326925800179577230 + 0. I) a

+ (0.327770888454982090 + 0. I) b) = -0.736196608749071 + 0. I,

(-0.590656319609631 + 0. I) ((-0.591008582207233624 + 0. I) a

+ (-0.589459378339369010 + 0. I) b) + (0.331003458223746

+ 0. I) ((0.331003458223746439 + 0. I) a

+ (0.327770888454981812 + 0. I) b) + (-0.735625969091165

- 0. I) ((-0.735625969091165288 + 0. I) a

+ (-0.738311510115613134 + 0. I) b) = 0.327869065042947 + 0. I

]

window 8 maple 12

[[a = 0.2249293777, b = 1.221244758]], 0.9888653482, "************"
[(0.737729376724384100 + 0. I) ((0.737729376724384100 + 0. I) a

+ (-0.738311510115612690 + 0. I) b) + (0.590656319609631053 - 0. I)

((0.590656319609631053 + 0. I) a + (-0.589459378339369122 + 0. I) b) +

(0.326925800179576676 - 0. I) ((0.326925800179576676 + 0. I) a

+ (0.327770888454982090 + 0. I) b) = -0.736196608749071002 + 0. I,

(0.590656319609631053 + 0. I) ((0.591008582207233624 + 0. I) a

+ (-0.589459378339369010 + 0. I) b) + (-0.331003458223746605 + 0. I) ((
-0.331003458223746605 + 0. I) a + (0.327770888454981812 + 0. I) b) + (
-0.735625969091165178 - 0. I) ((-0.735625969091165178 + 0. I) a

+ (-0.738311510115613134 + 0. I) b) = 0.327869065042946218 + 0. I]
7

## How to obtain the same accuracy?...

Let us consider the code

restart:
x := 11.1111111111;
Q := fopen("E:\\rezz.txt", WRITE):
fprintf(Q, "%e \n", x):
fclose(Q):
y := op(fscanf(Q, " %e\n"));
fclose(Q):

which produces

x:=11.1111111111
y:=11.1111100000 .

## accuracy of calculation in do loop....

Hello,

I want to calculate the IDs product :

## Accuracy of substitution...

I have a question about the accuracy of Maple functions subs and evalf. I have some expressions such as the following: (more complicated). Let's call it f(n).  f(n) is not a polynomial in n or a rational function. It is a function of n involving exponents and four operations. When I plug in a large n in such an expression, would the answer I get (using evalf with some custom accuracy) be exact?  I am trying to prove f(n)/n >= constant....

## Newton's Method in Maple...

Hello,

I'm doing a math assignment for numerical methods and I had to answer a question - solving Newton's method in maple to submit. I need to solve the question to an accuracy of 10^-5. I don't have access to the software right now as I only have it on the computers at our school, but I did take a maple course in my first year of university and have some experience with it. I wrote up this formula, but I'm not 100% sure if its correct. Could someone...

## problem with digits...

hi

i have written the followin code that achieve Y from determinant of matric aa. but when i change digit my result changes. i dont know why?

> restart;
> with(LinearAlgebra);
> Digits := 100;
>
> NULL;
> upsilon := .38;
> rho := 0.122e4;
> l := 0.176e-4;
> h := 2*0.176e-4;
> L := 20*h;
> NULL;
> E := 0.144e10;
> lambda := E*upsilon/((1+upsilon)*(1-2*upsilon));

## NLPSolve. Funny but nasty problem....

Dear all,

I have encoutered a funny problem with Optimization package. I minimize some long stuff (lets call it A) and get an answer, e.g.

[.116553990209052046e-19, [n = 4.24568325257496060, rhocut = 1.66125593854788400, m = 2.00000021862965971, rho = .956914761577446150]]

then i just do

evalf(subs(n = 4.24568325257496060, rhocut = 1.66125593854788400, m = 2.00000021862965971, rho = .956914761577446150, A));

and i get

## How to calculate coefficient of determination of a...

The coefficient of determination also known as R^2 tells how good a fit is. If R^2=1 the fit is perfect an if R^2=0 it's useless. But Maple don't have a native function to calculate R^2. I seached and found this:
http://www.mapleprimes.com/questions/40171-Determining-An-Equations-Accuracy

But it only describe how to calculate R^2 on a