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reduct2.mac is from the book "Perturbation Methods, Bifurcation Theory
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and Computer Algebra" by Rand & Armbruster (Springer 1987)
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it performs a liapunov-schmidt reduction for steady state bifurcations
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in systems of partial differential equations depending on one
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independent space variable.
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The example is from p187. maxima-5.9.0 cvs reproduces the
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(C1) load("reduct3.mac");
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Warning - you are redefining the MACSYMA function SETIFY
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ENTER THE NUMBER OF DIFFERENTIAL EQUATIONS
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ENTER THE DEPENDENT VARIABLES AS A LIST
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ENTER THE SPATIAL COORDINATE
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ENTER THE BIFURCATION PARAMETER
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ENTER THE CRITICAL BIFURCATION VALUE
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WE DEFINE LAM = ALPHA - 1
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ENTER THE CRITICAL EIGENFUNCTION AS A LIST
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ENTER THE ADJOINT CRITICAL EIGENFUNCTION AS A LIST
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ENTER THE DIFFERENTIAL EQUATION NUMBER 1
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ENTER THE DIFFERENTIAL EQUATION NUMBER 2
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'diff(y1,x,2)+alpha*y1-y2-y1^3-a*y1^5;
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[Y2, - Y2 + ---- - a Y1 - Y1 + (LAM + 1) Y1]
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WHAT IS THE LENGTH OF THE SPACE INTERVAL
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DO YOU KNOW APRIORI THAT SOME TAYLOR COEFFICIENTS ARE 0
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TO WHICH ORDER DO YOU WANT TO CALCULATE
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IS DIFF(W(AMP, 2 ,LAM, 0 ) IDENTICALLY ZERO, Y/N
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IS DIFF(W(AMP, 3 ,LAM, 0 ) IDENTICALLY ZERO, Y/N
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Dependent equations eliminated: (1)
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d W1 3 SIN(3 x) + 72 SIN(x) d W2 9 SIN(x)
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[----- = ----------------------, ----- = - --------]
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IS DIFF(W(AMP, 4 ,LAM, 0 ) IDENTICALLY ZERO, Y/N
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IS DIFF(W(AMP, 1 ,LAM, 1 ) IDENTICALLY ZERO, Y/N
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Dependent equations eliminated: (2)
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[--------- = - SIN(x), --------- = SIN(x)]
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IS DIFF(W(AMP, 2 ,LAM, 1 ) IDENTICALLY ZERO, Y/N
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IS DIFF(W(AMP, 3 ,LAM, 1 ) IDENTICALLY ZERO, Y/N
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Dependent equations eliminated: (1)
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d W1 69 SIN(3 x) + 2304 SIN(x) d W2
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[---------- = - -------------------------, ---------- = 18 SIN(x)]
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IS G_POLY( 1 , 0 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 2 , 0 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 3 , 0 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 4 , 0 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 5 , 0 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 1 , 1 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 2 , 1 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 3 , 1 )IDENTICALLY ZERO, Y/N
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IS G_POLY( 4 , 1 )IDENTICALLY ZERO, Y/N
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3 (- 1200 %PI a - 3195 %PI) AMP 3 AMP
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(D2) 3 AMP LAM + AMP LAM + ------------------------------ - ------
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(80 a + 213) AMP + 96 AMP
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(D3) [LAM = ---------------------------]
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(C4) taylor(%,amp,0,4);
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3 AMP (80 a - 75) AMP
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(D4)/T/ [LAM + . . . = ------ + ---------------- + . . .]
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