Hello!
I was hoping to contact you regarding a possible bug in the QSS1 simulator engine. For the following Lotka-Volterra model:
x(0) = 10 y(0) = 5 der(x) = x * 1.5 - x * y der(y) = -y * 3 + x * y
with quantum Q = 1, the output from PowerDEVS is while I believe the correct output should be
Time1 x1 Time2 x2 0 10 0 5 0.057142857 8 0.057142857 7 0.102597403 6 0.122077922 9 0.152236652 4 0.434247234 7 0.218903319 2 0.529485329 5 0.352236652 0 0.662818663 3 # 0.885040885 1 # 1.551707552 -1
I was wondering if you might be able to look into this and confirm whether this is correct?
The PDM file for the model is below.
Thank you!
Coupled { Type = Root Name = LotkaVolterra Ports = 0; 0 Description = Graphic { Position = 0; 0 Dimension = 600; 600 Direction = Right Color = 15 Icon = Window = 5000; 5000; 5000; 5000 } Parameters { } System { Atomic { Name = x1 Ports = 1 ; 1 Path = qss/qss_integrator.h Description = Quantized Integrator (QSS methods) with logartithmic quantization Graphic { Position = -2130 ; -2280 Dimension = 675 ; 675 Direction = Right Color = 15 Icon = %continuous%integrator.svg } Parameters { Method = Lst; 1%QSS%QSS2%QSS3%QSS4%BQSS%CQSS%LIQSS%LIQSS2%LIQSS3% ; dqmin = Str; 2 ; minimum quantum (Scilab) dqrel = Str; 0 ; relative quantum (0 : uniform) (Scilab) x0 = Str; 10 ; Initial state (Scilab) } } Atomic { Name = x2 Ports = 1 ; 1 Path = qss/qss_integrator.h Description = Quantized Integrator (QSS methods) with logartithmic quantization Graphic { Position = -2130 ; 795 Dimension = 675 ; 675 Direction = Right Color = 15 Icon = %continuous%integrator.svg } Parameters { Method = Lst; 3%QSS%QSS2%QSS3%QSS4%BQSS%CQSS%LIQSS%LIQSS2%LIQSS3% ; dqmin = Str; 2 ; minimum quantum (Scilab) dqrel = Str; 0 ; relative quantum (0 : uniform) (Scilab) x0 = Str; 5 ; Initial state (Scilab) } } Atomic { Name = GnuPlot0 Ports = 2 ; 0 Path = sinks/gnuplot.h Description = Plot input signal using GnuPlot Graphic { Position = 2220 ; -735 Dimension = 675 ; 720 Direction = Right Color = 15 Icon = %sinks%gnuplot.svg } Parameters { Inputs = Str; %Inputs ; Number of inputs Format = Str; set xrange [0:%tf] @ set grid @ set title 'Plot' ; General Formatting (use @ as line break) Format1 = Str; with lines title 'First output' ; Formatting options for input 1 Format2 = Str; with lines title 'Second output' ; Formatting options for input 2 Format3 = Str; ; Formatting options for input 3 Format4 = Str; ; Formatting options for input 4 Format5 = Str; ; Formatting options for input 5 } } Atomic { Name = Multiplier0 Ports = 2 ; 1 Path = qss/qss_multiplier.h Description = Multiplier. (QSS1 to 4) Graphic { Position = -255 ; -630 Dimension = 675 ; 675 Direction = Right Color = 15 Icon = %continuous%multiplier.svg } Parameters { Advance method = Lst; 1%Purely static%Estimate step% ; dQmin = Str; 1e-6 ; dQrel = Str; 0 ; } } Atomic { Name = WSum0 Ports = 2 ; 1 Path = qss/qss_wsum.h Description = y = K[0] * u0 + K[1] * u1 + ... + K[7] * u7 (QSS1 to 4) Graphic { Position = 645 ; -3660 Dimension = 675 ; 720 Direction = Up Color = 15 Icon = %continuous%sum.svg } Parameters { K[0] = Str; 1.5 ; K[1] = Str; -1 ; K[2] = Str; 0 ; K[3] = Str; 0 ; K[4] = Str; 0 ; K[5] = Str; 0 ; K[6] = Str; 0 ; K[7] = Str; 0 ; Inputs = Str; %Inputs ; } } Atomic { Name = WSum1 Ports = 2 ; 1 Path = qss/qss_wsum.h Description = y = K[0] * u0 + K[1] * u1 + ... + K[7] * u7 (QSS1 to 4) Graphic { Position = 645 ; 2040 Dimension = 675 ; 720 Direction = Down Color = 15 Icon = %continuous%sum.svg } Parameters { K[0] = Str; -3 ; K[1] = Str; 1 ; K[2] = Str; 0 ; K[3] = Str; 0 ; K[4] = Str; 0 ; K[5] = Str; 0 ; K[6] = Str; 0 ; K[7] = Str; 0 ; Inputs = Str; %Inputs ; } } Point { ConectedLines = 2 ; 5 ; 6 ConectedExtrems = Org ; Org ; Org Position = -675 ; -1950 } Point { ConectedLines = 3 ; 9 ; 12 ConectedExtrems = Org ; Org ; Org Position = -675 ; 1125 } Line { Source = Cmp ; 1 ; 1 ; 0 Sink = Cmp ; 3 ; 1 ; -1 PointX = -1350 ; 2085 ; 2085 PointY = -1950 ; -1950 ; -525 } Line { Source = Cmp ; 4 ; 1 ; -1 Sink = Pnt ; 1 ; -1 ; 0 PointX = -390 ; -675 ; -675 PointY = -450 ; -450 ; -1950 } Line { Source = Cmp ; 2 ; 1 ; 0 Sink = Pnt ; 2 ; -1 ; 0 PointX = -1350 ; -1350 ; -675 PointY = 1125 ; 1125 ; 1125 } Line { Source = Cmp ; 4 ; 2 ; -1 Sink = Cmp ; 2 ; 1 ; 0 PointX = -390 ; -675 ; -675 ; -1350 PointY = -150 ; -150 ; 1125 ; 1125 } Line { Source = Cmp ; 5 ; 1 ; -1 Sink = Pnt ; 1 ; -1 ; 0 PointX = 825 ; 825 ; -675 ; -675 PointY = -2835 ; -2400 ; -2400 ; -1950 } Line { Source = Pnt ; 1 ; -1 ; 0 Sink = Cmp ; 1 ; 1 ; 0 PointX = -675 ; -675 ; -1350 PointY = -1950 ; -1950 ; -1950 } Line { Source = Cmp ; 5 ; 1 ; 0 Sink = Cmp ; 1 ; 1 ; -1 PointX = 975 ; -2265 ; -2265 PointY = -3750 ; -3750 ; -1950 } Line { Source = Cmp ; 4 ; 1 ; 0 Sink = Cmp ; 5 ; 2 ; -1 PointX = 525 ; 1125 ; 1125 PointY = -300 ; -300 ; -2835 } Line { Source = Pnt ; 2 ; -1 ; 0 Sink = Cmp ; 3 ; 2 ; -1 PointX = -675 ; 2085 ; 2085 PointY = 1125 ; 1125 ; -225 } Line { Source = Cmp ; 6 ; 1 ; 0 Sink = Cmp ; 2 ; 1 ; -1 PointX = 975 ; -2265 ; -2265 PointY = 2850 ; 2850 ; 1125 } Line { Source = Cmp ; 6 ; 2 ; -1 Sink = Cmp ; 4 ; 1 ; 0 PointX = 1125 ; 1125 ; 525 PointY = 1935 ; -300 ; -300 } Line { Source = Cmp ; 6 ; 1 ; -1 Sink = Pnt ; 2 ; -1 ; 0 PointX = 825 ; 825 ; -675 ; -675 PointY = 1935 ; 1575 ; 1575 ; 1125 } } }
Hi Mehrdad, you are using QSS3 in the second integrator. Try using QSS1 on both integrator.
Best Fede
Oh my god, I thought I checked that they were both QSS1. Thanks you for catching it and apologies for the false alarm!
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Hello!
I was hoping to contact you regarding a possible bug in the QSS1 simulator engine.
For the following Lotka-Volterra model:
with quantum Q = 1, the output from PowerDEVS is
while I believe the correct output should be
I was wondering if you might be able to look into this and confirm whether this is correct?
The PDM file for the model is below.
Thank you!
Last edit: - 2016-02-15
Hi Mehrdad, you are using QSS3 in the second integrator. Try using QSS1 on both integrator.
Best
Fede
Oh my god, I thought I checked that they were both QSS1. Thanks you for catching it and apologies for the false alarm!