Hi.

in the ThermophysicalData[Chemicals] package that compute the coefficients for different species how I can find that coefficients for seven coefficients not nine of them

in other words, I am seeking to find Databases for the NASA Seven-Coefficient Polynomial Fits for Calculating Thermodynamic Properties of Individual Species.

Best

hello,

My equations are not getting solved.

Please tell me, is there any other command to solve these type of equations.

Q1.mw

I have an issue where I believe the values given by evalf (I have independent verification), but the plot of the same function is incorrect. Specifically, g(a) plotted for a <=0 is correct, and incorrect for a > 0.

What am I doing wrong?

g:=(a)->int(exp(-(x^2-a)^2),x=0..infinity)
plot(g(a), a=-2..5) #I don't believe anything for a > 0

evalf(g(-1)) #I believe all of these values
                          0.2059311656
evalf(g(0))
                          0.9064024772
evalf(g(1))
                          0.9868660750

Mattthew

DEAR SIR,

 I REQUEST YOU TO PROVIDE THE METHOD TO SOLVE THE FOLLOWING PROBLEM.

THANK YOU

The Fitting Procedure

The data are T,CP,H and S. I need to determine a polynomial with seven Coefficients.

The essential input to the fitting procedure is a table of specific heat, enthalpy, and entropy as a function of temperature. 

The constrained linear least-squares fitting procedure is a three-stage process. The first step is to determine simultaneously a1, through a5 for temperature ranges by fitting the specific heats to Eq. (1).

 The second step is to determine a6 for temperature ranges by fitting the H data. In this state, a1-a5 are held fixed, and as in the cp fitting, equality constraints on the fit and its first derivative are imposed at the common temperature. Finally, the a7 coefficients are determined by fitting the entropy (S) data.

R=1.987

DATA.txt

FITTING.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/FITTING.mw .
 

Download FITTING.mw

After running the program without any error, no plot obtained.

What is the reason?

Thanks3.mw

Hi, 

I try using the DeepLearning package.
I use the function Classify and, even in the simplest test case presented in the its help page (please look at it), I regularly get connection errors to the mpython server as soon as I execute classifier := Classify(...) or classifier(...) more than once.
Errors are one of these twos

Error, (in Train) unable to communicate with mpython server
or
Error (in Python:-EvalFunction) unable to communicate with mpython server

I work with Windows 7 Enterprise, on an 8 proc PC and 64 GB of memory. The worst situation happened when Maple didn't even return these errors and that I saw inflating the consumed memory in 2 minutes, forcing me to manually shut down my PC because the task manager wasn't no longer  operational.

Is it a known problem?
Could it be an installation problem?


Even if it's not the point here, I would like to say that trying to use the DeepLearning package is really challenging considering the poverty of the help pages.

Hello all

I wanna solve an optimal control problem and I have searched the Internet but I could not find any tutorial or video course on how to solve it with the Pontryagin maximum principle method. It is my first time that I want to use MAPLE for solving an optimal control problem and I would be thankful if someone can help me.

$$\max \int_{0}^{1} x_{2} [u(t)-u(t)^2] dt        $$

$$  \dot{x}_{0} = -(1-u(t)) x_{0}(t)+2 x_{1}(t) $$

$$  \dot{x}_{1}(t) = (1-u_{t}) x_{0}(t) +2 x_{2}(t) -[3-u(t)]x_{1}(t)  $$

$$   \dot{x}_{2}(t) = (1-u(t))x_{1}(t) -2 x_{2}(t)   $$

$$  0 \le u_{t}  \le \frac{1+t^2}{1+t}  $$

Thanks

Moving to online learning has proved difficult to get any real 1 on 1 time or with my teachers around this question, and the help I have got hasn't helped me as yet. 

I understand that asking for homework help is probably frowned upon but I would appreciate any help, guidance or direction on how to answer the below in Maple2019. 

The general formula for a plane in the 3D space is z = ax + by + c, where a, b, c are the parameters. Alice encodes three English words to three numbers by using the Maple command "text2num". She then set up a (3,4) secret sharing scheme with the idea of the Blakley method. The four shares are four planes given by: 

z =   4x + 19y + 2515211725275120 (mod 2515211819051461)

z = 52x + 27y + 2515210613496048 (mod 2515211819051461)

z = 36x + 65y + 2515210981587340 (mod 2515211819051461)

z =   6x + 60y + 2515211676449260 (mod 2515211819051461).

Find the secret English words of Alice with Maple command 

I'm absolutely hitting a wall. The most I have found in the word "you".

Thanks in advance. 

I have been stuggling with this for a few hours. I have my function 4x^2+9y^2. I have my point (2,1,25). I found my gradient to be 16i+18j. I want to plot the level curve that contains the point (2,1,25) and the gradient together. 

I know how to graph multiple level curves but not one.

Thank you in advanced!

I am so sorry for all of the questions. I am getting extremely frustrated with Maple. 

I want to plot a 3D rendering of 4x^2+9y^2 but I want the full paraboloid to show. However, all I keep getting is cut off versions.

I would like to factor an algebraic expression that contains exponentials.
Maple spits it back unfactored. Did I enter it wrong?

factor(exp(4*y) + 2*exp(2*y) + 1);

I want the legend to be produced to look like the third to last example. https://fr.maplesoft.com/support/help/Maple/view.aspx?path=plots/contourplot 

However, mine keeps coming out like this.

please help me

Download text.mw

Dear Community,

I have a four compartment flow model described with the following system of linear ODEs:

diff(L[1](t), t) = L[2](t)/T[21] - L[1](t)/T[12]

diff(L[2](t), t) = L[1](t)/T[12] - L[2](t)/T[21] + L[3](t)/T[32] - L[2](t)/T[23] + Q(t)

diff(L[3](t), t) = L[2](t)/T[23] - L[3](t)/T[32] + L[4](t)/T[43] - L[3](t)/T[34]

diff(L[4](t), t) = L[3](t)/T[34] - L[4](t)/T[43]

(For easier readability I’ve also described the problem in the attached FourCompartmentModelDescription.docx Word file.)

The time constants are as follows:

T₁₂ = 23.1481 d

T₂₁ = 5.4537 d

T₂₃ =  9.752 d

T₃₂ = 14.9007 d

T₃₄ = 8.8235 d

T₄₃ = 363.7255 d

Initial conditions are as follows:

L₁(0) = 2500.

L₂(0) = 589.

L₃(0) = 900.

L₄(0) = 37100.

Simulation should run from 0 to 400 d.

Could you pls. help me, to solve it numerically in Maple? As a solution I would need L₁(t), L₂(t), L₃(t) and L₄(t) both numerically and graphically. I used Maple to solve ODEs previously, but this time I don’t know, how to correctly specify the problem with an external, tabulated source. I’ve also prepared and attached a Maple worksheet, but did not try to run it yet. (FourCompartments.mw). The external Q(t) source for compartment 2 is attached as Source.xlsx. Should I've forgotten something, pls. let me know.

Your kind help is appreciated in advance,

best regards

Andras

MaplePrimesFourCompartmentModelDescription.docx

FourCompartments.mw

Source.xlsx