MaplePrimes - Maple 18 Posts and Questions

Cumulative histogram and corresponding polygon

CarlosRodrigues — Thu, 01 Jan 2026 18:53:25 Z

I have the following data

Dados:=[-9.43, -4.42, -4.04, -2.88, -1.90, -1.81, -1.20, -1.16, -1.03, -.14, 1.27, 1.72, 1.97, 1.98, 2.24, 3.24, 3.64, 3.8, 5.1, 5.52]

and using command

Histogram(Dados, binbounds = [-10, -7, -4, -1, 2, 5, 8], frequencyscale = absolute)

I can create a frequency histogram for the classes [-10,-7[, [-7,-4[, [-4,-1[, [-1,2[, [2,5[, [5,8[. However, how I can create a cumulative histogram with corresponding polygon employing this same information? With thanks.

substitute equation to equation

ashy — Tue, 17 Jun 2025 13:46:36 Z

I want to substitute equation to equation, how?

Download r.mw

Maple18 generates inconsistent outputs for the same expressions and commands

DG2025 — Sat, 05 Apr 2025 07:53:42 Z

I encountered this bizarre inconsistency issue that Maple18 generates different outputs when executing the same command:

test_res2:= factor( simplify( expand( value( subs( Perturbation_Sol, EQ_PX2_order_7 ) ) ) ) )

'EQ_PX2_order_7' is a rational expression in sin(i0), cos(i0), sin(uL), and cos(uL) with rational coefficient terms. It also has inert differentiation terms Diff( * , uL ).

'Perturbation_Sol' is a set of 171 elements in the form of 'parameter_name = expression'.

My goal is to check if substituting 'Perturbation_Sol' into 'EQ_PX2_order_7' yields 0. Since 'EQ_PX2_order_7' has inert differentiation terms, I've applied 'value' after using 'subs'. Then I apply 'expand', 'simplify', and 'factor' to reduce the result to the simplest form.

However, Maple18 generates different outputs when I just execute this repeatedly. Please see the worksheet "test.mw" for details. Any insight will be greatly appreciated! Also, I wonder if the same issue would happen when the worksheet is executed with newer versions of Maple.

EQN_SOL_test1.mla

test.mw

I encountered the problem with .m files originally. But MaplePrimes doesn't allow uploading .m files, so I had to save the expressions into the file "EQN_SOL_test1.mla", which is included in this question. Below we load the expressions from the .mla file first, and then save them into a .m file in order to recreate the problem that I encountered.

restart;

>	read "EQN_SOL_test1.mla": # Load 'EQ_PX2_order_7' and 'Perturbation_Sol'

>	save EQ_PX2_order_7, Perturbation_Sol, "EQN_SOL_test1_m.m"; # Save the expressions into a .m file

Now we demonstrate the inconsistency problem with .m files. Notice that Maple generates 3 possible outputs:

The last 2 outputs cannot be reduced to 0 since is nonzero as shown below.

>	plot3d( 5cos(i0)^2cos(uL)^2-7cos(i0)^2-5cos(uL)^2+4 , uL=0..2Pi, i0=0..2Pi );

restart;

>	read "EQN_SOL_test1_m.m":

>	length( EQ_PX2_order_7 );

(1)

>	length( Perturbation_Sol );

(2)

>	numelems( Perturbation_Sol );

(3)

>	Perturbation_Sol[1..5]; # Just to give an example of what the elements in 'Perturbation_Sol' look like

(4)

>	for j from 1 to 50 do test_res2:= factor( simplify( expand( value( subs( Perturbation_Sol, EQ_PX2_order_7 ) ) ) ) ); end do;

(5)

It seems that with .mla files the problem occurs in a different way! With "EQN_SOL_test1.mla", the outputs for all 50 iterations stay the same as

(A)

but they may all change to the following different result after retarting many times:

(B)

In particular, after a large number of test runs (i.e., open the file "test.mw", execute the worksheet, close the file, and repeat), the result (B) has only occured twice. The second appearance is saved here for you to view. Once you re-execute this worksheet, most likely all outputs below will change back to (A), and (B) will only reappear after a large number of reruns.

restart;

>	read "EQN_SOL_test1.mla": # Load 'EQ_PX2_order_7' and 'Perturbation_Sol'

>	for j from 1 to 50 do test_res2:= factor( simplify( expand( value( subs( Perturbation_Sol, EQ_PX2_order_7 ) ) ) ) ); end do;

(6)

Download test.mw

Error, (in dsolve/numeric/bvp/convertsys) f(x) and f cannot both appear in the given ODE

Saha — Wed, 02 Apr 2025 18:25:34 Z

HIPT.mw

Could you please help me to solve this error.

the roots of a big polynomial

Hanskira — Tue, 01 Apr 2025 17:04:49 Z

Hey everyone,
I am trying to find the roots of a very large polynomial, specifically targeting the leading Fisher's zero (the root with the smallest positive imaginary part). I'm using Maple's RootFinding[Analytic] package with Digits := 10, but the results only show 5-digit accuracy (see the attached file plz)

Why does RootFinding[Analytic] fail to achieve full 10-digit precision despite the Digits setting? Are there hidden limitations or optional parameters to improve this?
Are there alternative methods in Maple to accurately locate only the leading zero (without computing all roots in a region)?
Root_Poly.mw

how to give a limit value from -1 to 1 for sensitivity analysis

ashy — Sat, 29 Mar 2025 12:23:08 Z

I will look for sensitivity analysis for parameters in the epidemic model using the normalization formula, the result should be between -1 to 1 but there are 2 parameters whose values are more than 1, how do I set the limit so that the sensitivity value is between -1 to 1?

Warning, The imaginary unit, I, has been renamed _I

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(11)

Download sensitivity.mw