Thomas Dean

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15 years, 223 days

MaplePrimes Activity

These are replies submitted by Thomas Dean

@Joe Riel 

I tried this with ngspice-28.  The result was similar to using the IdealOpAmp in the above ckt.

I re-ran the filter design tool and got the same design.pdf.  I sent an email to  No reply, yet.

@Joe Riel 

Here is the design file from Design.pdf

Look at the comments in my question.  This is a 4th order Butterworth. stated 10db gain and 3db down at 2kHz.  Looking at the component values, I questioned the performance.

Syrup gives very different results.

I get similar results to yours.

The netlist is from  When I first saw the component values, I suspected the results, so I tried Syrup.  Syrup shows a much wider bandpass and 30db less gain.

@tomleslie  Thanks.  I just cut-paste and run,  Should read first.


limit(subs(theta2=theta1,soln[3]),theta1=0,left); ## or right

This is identical to one of the pdsolve examples, except the example uses

(D[2](u))(x, 0) = 0

as one of the initial conditions.

@Rouben Rostamian  

Linux, Maple 2016, 4.2GHz I7.

All I see is the cone with the minimal height cylinder.  Any ideas?

@Rouben Rostamian  

I use X with twm.  I do not use a desktop.

When an application's window is minimized, it is displayed as an icon.  This is not a maple toolbar thing.

The icon used for maple is maple2016/bin/Maple2016.png.  There is no maple2016/data/start directory.  There is a maple2016/data/start

searching the maple2016 directory tree for *.png finds 241 files.  only one file has maple in its file name, of any case, and that is maple2016/bin/Maple2016.png.

Most, if not all, the icons in the maple2016 tree appear to be for toolbars or the start page.  The largest is 75x75 pixels.


The Tools/Options dialog has a setting for large icons on the toolbar.

If I start maple, choose Help, then minimize (iconize) the window, the displayed icon is very small.  Same for maple.  Start maple, then minimize (iconize) the window, the displayed icon is very small. 

I think the help icon is built into maple help??

The maple icon is maple2016/bin/Maple2016.png.    If I could find a larger version of that icon, it would make my use easier.

I do not think the polynomial you specify, with all coefficients positive, has a positive root.  Assuming positive does not include zero or complex.

assume(a > 0, b > 0, c > 0, b^2 >= 4*a*c)
eqn := a*x^2+b*x+c = 0
soln := solve(eqn, x)
for s in soln do
  if verify(s, 0, greater_than) then
    print("Greater than", s)
    print("Negative", s)
  end if
end do


@Preben Alsholm The NASA paper,

was aimed at deriving constants for use in RK methods.  How the 'exact solution' was determined was not mentioned.  The problem I was looking at is given on page 38. 

A second PDE example if given on page 40 of the paper.  But, pdetest does not verify that this is a solution...

Tom Dean

Use 'create a new document block or enclose the current section in one' followed by 'insert a maple prompt after the current execution group'

Sorry for the noise.

Tom Dean

@Carl Love I am on x64 Linux. (core i7, OC 4.2GHz, 16G RAM)

I have default axes names defined in .mapleinit.

I use emacs as my interface to command line maple.  So, the double underscore remains a double underscore.  With xmaple,  the double underscore produces subscript, visually.  This should be a keyboard shortcut.  But, in xmaple, using

p__1 - p[1];

does not result in zero.  I wonder why, since they are visually the same.

p__1 := 7; p[1];

Shows that things that are visually the same are not.

This is the same with command line maple.

@Carl Love Old UNIX habit...

(a,b) := op(calcView(relBrgLinePlot,relTgtPositPlot,relTgtLinePlot));
                    a, b := 0. .. 95., -61.58179461 .. 16.

viewArg := [floor(op(1,a))-10..ceil(op(2,a))+10,
                      viewArg := [-10 .. 105, -72 .. 26]

        title="Relative Motion",
        labels=["Miles, +North","Miles +East"],
        gridlines = true,

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