## Vintage x~'s

by: Maple
There is a general problem which arises when one uses assume() that can be quite confusing. I seems that once an x~ is passed on by assigning a data structure containing it to another name, it becomes an entity on its own, a sort of vintage x~, with no connection back to the original variable on which the assumptions were made. It has no unique name and no way to access it for manipulation or redefinition. The code x:='x' does not affect these vintage x~'s. Even the function addionally() does not affect these vintage x~'s. Thus one can have a whole set of x~'s of different vintage in one's data structures with no way to tell them apart or manipulate them. This has tied some of my codes in knots before I realized what was happening. It would be so much less frustrating if each new vintage received a unique name that could be referenced by the user.

## Showing students the steps in a problem from symbols,...

by: Maple
I have seen a number of forum questions concerning showing students the steps in a problem. There seems to be some confusion about how to do this reliabley and easily. A method I have found useful is seen below:

I have Maple worksheets a.mws and b.mws in directory C:\maplecode. I’ve set this directory to be the current directory by executing the command currentdir(“C:\\maplecode

## Can't plot proc - why?...

Hi, I have a proc that generates a "piston" plot in 2-D. I generate this with a procedure. Calling the procedure works, but calling it from Plot3d doesn't. I'm really not sure why. I'd appreciate the help. My stuff is below: Diameter := 46; Shape := proc (x,y) if((x^2+y^2)^(0.5) <>

## how to make maple show all calculations....

hello, i just started using maple in school and i was wondering if i can make it show all calculations. it always gives a nice answer but im wondering it if can show me all step by step and not just the answer so it will help me learning. thanks in advance.

btw i tried looking in the manual and using google, but didnt find anything.

jenni

## call a procedure from a differential expression...

I have an expression of the form diff(var_name(t),t)= -K + procedure_name(var_name(t)) where K is a constant. The procedure is a boolean function. the var_name(t) is not recognised as a numerical value in the procedure and an error is reported. Any suggestions greatly recieved. The actual procedure is shown below. > restart: > m:=1: > P:=10: > RLLS:=proc(vt) > local max,v,N,k,feq,mu,lambda; > max:=.01: > v:=vt: > N:=9.807: > k:=.0001: > feq:=10: > mu:=2: > if abs(feq/mu*N)

## Algebra with generic polynoms/rational fractions...

Hi all. Is it possible to construct a generic polynom of degree n with generic coefficients a1 a2 .. an ? I would like to be able to write things like Sum(a_i X^i, i=1..n) in all generality. How to specify the coefficients (lists, arrays .. what ? ) ? Afterwards, the goal would be to be able to get the numerator and denominator of a sum of rational fractions indexed somehow by i plus a set of very generic coefficients a_i. Any hint of how to do this kind of manipulation is most welcome, even in the simple case where we are given the value of n from the beginning. Thank you for your attention.

## Extracting coefficients of a variable in an expres...

I wish to extract the coefficients associated with a particular variable. I have assigned the results of a symbolic solve of a system of equations (sol) using assign(sol): One of the assigned variables in (sol) is ROLL and the symbolic solution is of the form ROLL; 200*a*b^2*VAR1 + 3000*b*VAR2 + 1500*cos(c)*d*VAR1 . . . (the actual expression is hundreds of line long and each VAR is randomly distributed in the expression) How do I isolate the coefficients associated with a specific VAR eg for VAR1 I want to be able to make the assignment coefVAR1:=(200*a*b^2)+(1500*cos(c)*d)

## Maple 8.0 and Fedora Core 5...

I use to own a old Maple version 8.0 since the RedHat 6.0 days. I have been able to make it run till FC3 (with export LD_ASSUME_KERNEL=2.4.1 and with a new JRE). However, recently, I upgraded the system to FC5 (kernel 2.6.15) from FC3 (I did not try FC4) and Maple stopped working. I've used the "export LD_ASSUME_KERNEL=2.4.1". The error I get is : \$ /opt/Maple8.0/bin/maple /bin/sh: error while loading shared libraries: libdl.so.2: cannot open shared object file: No such file or directory /opt/Maple8.0/bin/maple: line 162: /opt/Maple8.0//cmaple: No such file or directory A ldd on libdl.so.2 gives

## Labelling columns with ColumnGraph...

Hi, I've been trying to label the columns of a column graph I created using the ColumnGraph command. But I just can't figure out how to do it. Any tips?

## Reverse y-axis direction...

In structural engineering the y-axis direction in beam deflection calculations is reversed. A negetive deflection is an upward deflection. I need to plot the deflection. A simple reflect command will do part of the trick, but the tickmarks are not reflected. How do I reverse the y-axis direction so it will be negetive to positive from top to bottom? Thanks.

## Derivative Syntax...

This is my first time using Maple - so I don't even know where to start... Hopefully I can make this clear... example problem: f(x) = 2.3x g(x) = ax^3+bx^2+cx+d h(x) = px^2+qx+r l(x) = kx^3+mx^2+nx+s I was able to find the correct syntax for Maple to calculate the first and second derivatives of the functions above. Now I have to write out a system of equations using the original functions and their derivatives...once I have the system of equations then I need Maple to solve for each variable...what is the proper syntax for all of that? Also, for Maple to calculate the derivative I used "diff(f(x),x)" and "diff(f(x),x\$2)", so how do I get those derivatives into my system of equations?

## Maple implementation of Geddes-Newton Multiple Int...

Hello, Earlier this year I reached an impasse with Maple's numerical integration package over the need for a high-resolution (say 50 or more digits) evaluation of multiple integrals for a Bayesian statistics application. An integral such as sqrt(1.+4.852800000000*chi^1411+5.887416960000*chi^200+4.852800000000*chi^100+5.887416960000*chi^2822-21.48043392000*chi^100*chi^1411) over a rectangular range like chi=0..0.9999,chi=0..0.9999999 would return unevaluated. Infolevel[`evalf/int`] explained that the methods available in Maple would not return the required precision. But the problem persisted even when I swallowed my pride and settled for 12 digits of precision. Stuck as I am, I haven't even tried to present the problem to Maple in higher dimensions.

i'm curious if exist any possibility to make a procedure like

myproc:=proc(x,y)
.
.
.
endproc

and then assign to it a typesseting rule which display statement

myproc(x,y)

to

x (some symbol) y

## document layout...

hi everyone,
i'm trying do a tamplate for solving school problem. I need only input some variables at begining and it's should give me whole solution. But i need to print it so i have to use this layout style:

i have:
f:=y=x+5
then i use:
subs(x=2,f)

i wanna have inline form
y=x+5=2+5=7
but i can get only
f=y=x+5subs(x=2,f)=7
this is just for examle of layout i want to get but i don't know how...
if i turn off input the subs(x=2,f) dissappear but gap still remines..

btw does exist a statement by which can i control if expreson is inline or not?
﻿