Revisions to Does version 11 have this bug in FourierSeries?

deleted 2 characters in body

Source Link

edited Mar 27, 2017 at 15:51

33.5k
3
112
178

Bug introduced in 7.0.1 or earlier and persisting through 11.0.1

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

Bug introduced in 7.0.1 or earlier and persisting through 11.0.1

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

Bug introduced in 7.0.1 or earlier and persisting through 11.1

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

Modified bug header

Source Link

edited Mar 13, 2017 at 22:26

bbgodfrey

63.2k
18
96
170

Bug introduced in 97.0.1 or earlier and persisting through 11.0.1

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

Bug introduced in 9.0 or earlier and persisting through 11.0

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

Bug introduced in 7.0.1 or earlier and persisting through 11.0.1

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

added 76 characters in body; edited tags

Source Link

edited Mar 13, 2017 at 21:05

Szabolcs

239.2k
32
654
1.3k

Bug introduced in 9.0 or earlier and persisting through 11.0

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

Bug introduced in 9.0 or earlier and persisting through 11.0

I am using version 10.0 with Apple OS X. Consider the following.

f[t_]:=1/(1+25.0*(t-0.3)^2);
Plot[f[t],{t,-1,1}]

Below FourierSeries retruns the wrong series.

WrongSeries[t_]=Chop@Expand@ExpToTrig@FourierSeries[
f[t],t,4,FourierParameters->{1,\[Pi]}];
Plot[WrongSeries[t],{t,-1,1},
PlotLabel->Style["The Wrong Truncated Fourier Series",14,Bold]]

Does Version 11 also have this problem?

-----EDIT-----

I can derive the right series using a combination of FourierCosSeries and FourierSinSeries.

RightSeries[t_]=Expand[(
FourierCosSeries[f[t]+f[-t],t,4,FourierParameters->{1,\[Pi]}]+
FourierSinSeries[f[t]-f[-t],t,7,FourierParameters->{1,\[Pi]}])/2
];
Plot[{f[t],RightSeries[t]},{t,-1,1},
PlotLegends->{"g[t]","Truncated Fourier Series"}]

bugs fourier-analysis

Tweeted twitter.com/StackMma/status/840888770400522241

occurred Mar 12, 2017 at 11:34

I provided a workaround.

Source Link

edited Mar 12, 2017 at 0:14

Ted Ersek

7.2k
21
42

Loading

Source Link

asked Mar 11, 2017 at 19:07

Ted Ersek

7.2k
21
42

Loading

Stack Exchange Network

Return to Question

Post Timeline