Maplesoft regularly hosts live webinars on a variety of topics. Below you will find details on upcoming webinars we think may be of interest to the MaplePrimes community.  For the complete list of upcoming webinars, visit our website.

Case Study: Transforming a University's Placement Testing Process

This webinar will feature the story of how the University of the Virgin Islands moved their placing testing process from paper and pen to using the Mathematical Association of America’s (MAA) placement tests offered through the Maple T.A. testing environment. Instructors at the university now handpick questions to create their own placement tests that best fit the course they are teaching. From there, they are able to analyze the data and craft lessons based on student performance. The end result is that students are more satisfied with the education they are receiving and instructors have made enormous gains with regards to efficiency and flexibility.

To join us for the live presentation with Dr. Celil Ekici from the University of the Virgin Islands, please click here to register.

Getting Started with Maple

This webinar is designed for the user who comes to Maple for the first time. It will demonstrate “how to get started” by clarifying the user interface and the ways math can be entered into Maple, and then “processed.” Coverage includes

• Entering mathematical expressions and interacting with them in a syntax-free way.
• The difference between input in mathematical notation and “linear” or text form.
• The role of the Context Sensitive Menu system for interacting with mathematical objects.
• Graphing and interacting with various types of graphs, including animations, surfaces, and implicit plots.
• Use of built-in tools such as Assistants, Tutors, and Task Templates.
• The Maple help system and the Maple Portal.
• Introduction to differential equations and matrix manipulations.

To join us for the live presentation, please click here to register.

Help me with this:

I have a differential equation:  s:= diff(h(t),t) = -0.1738137398e-2/sqrt(2.8-h(t))

Solution is: h(t) = 14/5-(1/100000000)*2607206097^(2/3)*t^(2/3), h(t) = 14/5-(1/100000000)*(-(1/2)*2607206097^(1/3)*t^(1/3)-(1/2*I)*sqrt(3)*2607206097^(1/3)*t^(1/3))^2, h(t) = 14/5-(1/100000000)*(-(1/2)*2607206097^(1/3)*t^(1/3)+(1/2*I)*sqrt(3)*2607206097^(1/3)*t^(1/3))^2

And i have to need a plot... so i use complexplot and recive a mesage:

Error, (in plots:-complexplot) invalid input: `plots/complexplot` expects its 2nd argument, r, to be of type {range, name = range}, but received h(t) = 14/5-(1/100000000)*(-(1/2)*2607206097^(1/3)*t^(1/3)-((1/2)*I)*3^(1/2)*2607206097^(1/3)*t^(1/3))^2

Help me if you can!! Thank you so much!!! 

Good afternoon.

I request your valuable suggestion for the above cited subject.

I here by uploading the file for your kind notice.

Hey,

I've been trying to divide an equation into matrixes, with not a lot of luck.

Simple example:

A=2b remade into [A]=[2]*[b]

This is a basic overview of the problem, i need it to work with bigger matrixes.

Thank you in advance.

I am solving a system of ODEs with dsolve(ODES, numeric, method = lsode[adamsfull]) and I noticed that some of the solutions are really small numbers, of the order of 10^-{10} and smaller. Certainly for all intents and purposes I will treat those as zero, but my question is: what flag do I set in dsolve to force Maple stop seeking for a solution when it is so close to zero and set it to 0.0? It seems like a great waste of computational time to try and find the significant digits of the order one number in front of 10^{-10} for any particular solution, at least in my case. So, is there a way to add some option in dsolve such that maple sets that to zero before trying to fully calculate it fully (i.e. all the significant digits) ?? I have looked at abserr and relerr but that does not do the trick. 

IF the question was asked before, forgive me. I have tryed to find an answer within the search here and on the maple help page but was unsuccessful. 

This should be trivial but I am not able to figure out the right syntax to execute it

The pdf is given by :

f_X(x)={ 1/25 *x, 0<=x<5

             2/5 -x/25, 5<=x<10

             0, otherwise

I have tried to use the "CumulativeDistributiveFunction" so far

I’ve been having some issues working with large datasets / matrixes in maple 17.02 and 2015. My data consists of a 10^7 x 14 csv file with several lines of header information. Attached is a small sample. The ImportData assistant hangs while importing said file. The javaw process stops responding for a period of time then stops consuming cpu time. I’ve have successfully imported a file of the same format but reduced in size (10^6 x 14) with this same function. So I don’t believe it’s a formatting issue but rather its size.

Are there size limitations to the ImportData function?

The attached maple file has a test case in which the data set (sans header info) is created and exported as a csv file. The export time took longer than I expected (~2 hrs). I then attempted to import the file using two different functions. The ImportMatrix function successfully imported the test case file in approximately 20 minutes, however the ImportData functions seems to fail in the same way as it does importing my actual dataset. I haven’t successfully used the ImportMatrix function on my actual dataset; I’m assuming the header information is the source of the problem.

Are there other methods to import this data?

As stated above, I’m tried both maple 17 and 2015 both 64 bit versions running on an Intel i7 M620 @ 2.67Ghz, 8 GB ram (~ 6 GB avail), sata 2 ssd.

Thank you,

Ron

importtest.mw  Sample.txt

I have to solve a numerical problem and I was wondering how to make maple treat very small numbers as zero. Say I do not care about anything less than 10^-5, so maple should treat all such numbers as zero. How to set this behaviour for the entire session? Thanks!

Hi!

I am trying to solve a large nxl system of coupled differential equations. Maple seems to have trouble even for small n's so I wanted to know if anyone has any suggestions. Take the case of the following system of ODEs for my unknown functions f[0,0](x) and f[1,0](x). 

ODEs:= {diff(f[0, 0](x), x)+2.*f[0, 0](x)/x^5+.5000000000*f[0, 0](x)/x = -15.58845727*sin(.5773502693*x)/x^2+140.2961154*sin(.5773502693*x)/x^4-81.*cos(.5773502693*x)/x^3, diff(f[1, 0](x), x)+6.*f[1, 0](x)/x^5+1.500000000*f[1, 0](x)/x-1.*f[0, 0](x)/x = -15.58845727*sin(.5773502693*x)/x^2+25.98076212*sin(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^2+140.2961154*sin(.5773502693*x)/x^4-233.8268591*sin(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^4-81.*cos(.5773502693*x)/x^3+135.*cos(.5773502693*x)*(1/x^4)^(1/4)*exp(1/x^4)*GAMMA(.7500000000, 1/x^4)/x^3-20.78460970*sin(.5773502693*x)/x^6+6.000000004*cos(.5773502693*x)/x^5+62.35382908*sin(.5773502693*x)/x^8-36.00000002*cos(.5773502693*x)/x^7, f[0, 0](.1) = 1.503497680, f[1, 0](.1) = -.5011660086}

Following Preben Alsholm's suggestion from my previous thread I am using lsode[adamsfull], since no other method i have tried worked for this problem. I am currently using:

Sollsodefull:=dsolve({ODEs}, numeric, method = lsode[adamsfull])

and it seems to work. I am wondering if there is a way to optimize this, as I will be extending my problem to n and l much larger than order unity numbers, therefore my system will contain about 10^4-10^5 equations. Solving this symple system of 2 equations takes a bit less than a second, but still it takes some time for the processor on my MBP. I am affraid it will be a nightmare for the full problem. Whats the most optimal dsolve option for this kind of problem? Any ideas?

I have also attempted dverk78, rkf45,rosenbrock, lsode(without the adamsfull option), and all failed for this particular system. Errors were:

1. For rkf45: Error, (in f00) cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up

2. For dverk78: Error, (in Soldverk78) cannot evaluate the solution past .1, step size < hmin, problem may be singular or error tolerance may be too small

3. For rosenbrock: Error, (in dsolve/numeric/SC/firststep) unable to evaluate the partial derivatives of f(x,y) for stiff solution

4. For lsode without [adamsfull]: Error, (in Sollsode) an excessive amount of work (greater than mxstep) was done

5. For default method with stiff=true and inplicit=true options: Error, (in dsolve/numeric/SC/firststep) unable to evaluate the partial derivatives of f(x,y) for stiff solution

Dear all,

I want to use the Maple Compiler to improve the performance of some of my codes. To get used to it, I tried doing the examples from the ?Compiler help-page, but everytime I run the compiler, I get the error message:

"Error, (in Compiler:-Compile) compiler exited with nonzero status 1: 

Do some of you know a possible reason for this?

Thank you all.

Download test.mw

I am not aware if is a problem with me or else.

Have some questions about the select command and (possible) big tensorial expressions. I think it would be a simple question to manage, but I still have problems.

TensorEnergiaMomento.mw

Thanks a lot

When solving a nonlinear differential equation on some variable x, but using some other parameter w, I am finding on Maple some complicated solution, which I would like to simplify by making evident what is the x dependence, and where I can compact complicated functions of the parameter w alone into new constants. How can I do that automatically?

For example, to have

(sinh(w) + ln(w))*x 

to be automatically called

c*x

Thank you in advance.

Hello.

given this expression

T:=unapply((1/6930)*exp(-(1/7938)*(X[4]-933)^2)*exp(-(1/6050)*(X[2]-805)^2)/((1+exp((1/50)*X[4]-(1/50)*X[2]))*Pi),X[2]);

U := unapply(sum(T(X[2]), X[4] = 0 .. 3600), X[2]):

I want to display U, but not all 3600 terms. is there anyway to simplify/reduce this sum?

kind of like geo series a+ar+ar^2+ar^3+...+ar^(n-1)=sum(ar^k,k=0..n-1) can be reduced to a*(1-r^n)/(1-r)

Hello. Earlier, I asked about it, (see http://www.mapleprimes.com/questions/203573-How-To-Do-Simple-Operations-On-Tensors). However, not all I was able to understand. Below I will give a try, and maybe you'll show me where I'm wrong.

Also, I'm interested in how you can determine the components of the tensor in a different coordinate system connected with the original in any conversion. Thank for your help.

Download 1.mw

I am trying to explore the equality of two lengthy expressions. Unfortunately, my relations that all are symbolic, are lengthy and I use 'verify' command to explore the equality of them. When I use this command the 'FAIL' message appears. Maybe it is because of lengthy expressions and Maple cannot exploring equality of them. I have attached the corresponding file. Does anyone know what's the real problem? Thanks in advance.

MMatrix.mw