## 60 Reputation

15 years, 188 days

## Problem Plotting DE...

Maple
Hey guys, I want to plot a differential equation (I'm looking for something a 2d direction field plot) The differential equation is a composition of piecewise functions and a cubic spline. I have to use the subs() call to convert the function h(t) into a numeric (i dont really understand this part but was told to do this). Anyways I need the DEplot error explained to me. Here I show all of the relavent code leading up to the error: with(CurveFitting): with(DEtools): z := t -> 4.713*sin((1/22356)*Pi*t)+.743*sin((1/21600)*Pi*t)+.964*sin((1/22788)*Pi*t)

## Help me with an error with calling a spl...

Maple
Hey guys, I am trying to plot a direction field using Maple 11.: //*** first I define the spline, this is the function that is giving me the error with(CurveFitting); BasinArea := H -> Spline([[-10, 36000000], [-8, 47000000], [-6, 57000000], [-4, 70000000], [-2, 81000000], [0, 89000000], [2, 95000000], [4, 100000000], [6, 105000000], [8, 111000000], [10, 125000000]], H, degree = 3) ; //*** then I define the two other functions that are used in the DE (error is not in these but I include them for //*** completeness)

## Why isnt this function plotting properly...

Maple

Ok, i am trying to plot the function abs(H)^(1/2) * sign(H). This function should be negative when H is negative, but for some reason the " * sign(H) " is having no effect on the plot, the plot is an even positive function rather than an odd function as it should be.

When I manually evaluate this function with a negative H using maple, a negative value is given back to me, however not in the plot... why is this.

## How to plot a multi-coloured, 2d vector ...

Maple

Hey its Paul, I have another similar post to this one where I ask this question as a continuation of a question I had previously asked. However I am going to keep the two questions separate.

At each point I have the same data as I had in the previous question:

c:  an integer from 1-5 specifiying which differential equation was used to calculate the z value at this point (this information shold be represented by different coloured vectors)

x: this is just the x position of the data point

y: this is just the y position of the data point

## How to make a multi coloured, 3d plot, f...

Maple

Hey guys, I am currently writing a dynamic programming program. This program is used to simulate and optimize turbine operations.

The program produces a grid of nodes. At each node (each node has an X and Y coordinate), one of 5 differential equations is evaluated. A flag indicating which differential equation was used, as well as the dZ from the DE is stored at each node.

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