## 30 Reputation

2 years, 175 days

## How to use Explore() for multiple expres...

Maple

I want to use explore commad in order to make a plot along with calculating another expression,simultaneously.

The following command does not give the desired result:

Explore([plot(a*x^2+b*x^3,x=-2..2),evalf(a^2+b^2)],parameters = [a = -1.00..1.00, b=-1.00..1.00],placement=right );

I want to have a diagram which depends on both "a" and "b" together with evaluation of the expression "a^2+b^2" somewhere near the control markers.

I appreciate if any one could help.

Thank you very much

## A special issue on dsolve numeric...

Maple

Hi everybody

My question comes back to singularities within a differential equation.

Consider a Non-Linear differential equation of y(x), say Eq1.

When we solve this with dsolve ({Eq1, ICs}, type=numeric) we can extract the value of y(x) for each independent variable x.

Now if Eq.1 admits a singularity (for example at x=x0) that can not be removed the following message appears:

Error, (in unknown) cannot evaluate the solution further left (right) of x0, probably a singularity.

By left(right) Maple means that the solution cannot be evaluated for x<x0 (x>x0).

However, in some situations, the Linear form of Eq.1 behaves regularly for all of the values of x, I call the Linear equation as Eq.2.

Now my question is:

How can I make a conditional expression with proc and for commands that do the following requirements:

1. Detect the singular point x0 by running a loop over x for the numerical solution of Eq.1 and write the value of x0 for different initial conditions , since the value of x0 depends on initial conditions.

2. Find the value of y(x=x0) by solving Eq.2 as the linear equation is no longer singular at x=x0.

I want to find out the suitable algorithm through which I can perform the above procedures.

Thank you very much and best regards.

## A question on interpolation function...

Maple

Hi everybody

I have a problem with finding the interpolation function from a data list.

In Mathematica I can find the interpolation function from a set of data simply as below:

data := {{13, -2}, {12, -1}, {11, 0.0}, {10, 1}, {9, 2}, {8, 3}, {7,
4}, {6, 5}, {5, 6}, {4, 7}, {3, 8}, {2, 9}, {1, 10}}

g := Interpolation[dat]

Plot[g[x], {x, 1, 9}] (see the attached file for the diagram)

The mathematica software gives simply the interpolating function and then we can work with it.

However, I cannot do the same procedure with maple.

Would you be so kind as to let me know how can I make an interpolating function for these set of data in maple?

Thank you very much and best regards.

## How can I plot a function from higher to...

Maple

My question deals with plotting a function, namely, x(t), from lower to higher values of t.

To this aim, I solved a simple differential equation with given initial conditions and then plotted for the result.

As it is seen, maple starts from lower values of t to higher ones. However, is there a command through which I can reverse the plotting procedure?

From the attached file, "A question on plotting", we see that the slope of the curve at t=2 is positive when we observe it from "left to right". However, this slope is negative once we start plotting from "right to left".

Is there any command with which I can start plotting from right to left? or change of axis origin?

I would appreciate for your kind help and support.

My best regards