(* d_kp2ddy.m *) (* Menu item 2-5 *) (* Last Updated: 14 June, 2009, 14:35, 12:30 by DP at CSM *) (* One specific version of the KADOMTSEV-PETVISHVILI (KP) EQUATION *) (* where a y-derivative has been applied to each term. *) eq[1] = D[u[1][x,y,t],x,y,t] + alpha*(D[u[1][x,y,t],y]*D[u[1][x,y,t],{x,2}] + u[1][x,y,t]*D[u[1][x,y,t],{x,2},y] + 2*D[u[1][x,y,t],x]*D[u[1][x,y,t],x,y]) + D[u[1][x,y,t],{x,4},y] + sigma^2*D[u[1][x,y,t],{y,3}]; (* NOTE: To put the y-differentiated KP equation in evolution form, *) (* y and t must be interchanged. Then an auxillary dependent variable *) (* is be introduced, forming a system. The evolution system for the *) (* y-differentiated KP equation is *) (* eq[1] = D[u[1][x,y,t],t] - u[2][x,y,t]; eq[2] = D[u[2][x,y,t],t] - u[3][x,y,t]; eq[3] = D[u[3][x,y,t],t] + (1/sigma^2)*(D[u[2][x,y,t],y,x] + 2*alpha*D[u[1][x,y,t], x]*D[u[2][x,y,t],x] + alpha*u[2][x,y,t]*D[u[1][x,y,t],{x,2}] + alpha*u[1][x,y,t]*D[u[2][x,y,t],{x,2}] + D[u[2][x,y,t],{x,4}]); *) diffFunctionListINPUT = {eq[1]}; numDependentVariablesINPUT = 1; independentVariableListINPUT = {x, y}; nameINPUT = "the Kadomtsev-Petvishvili Equation (with an added y-derivative"<> " applied throughout)"; (* noteINPUT = "To create evolution equations with respect to the t-variable, "<> "the variables y and t have been switched with each other in the "<> "equations given to the program." *) parametersINPUT = {alpha}; weightedParametersINPUT = {}; userWeightRulesINPUT = {}; rankRhoINPUT = Null; explicitIndependentVariablesInDensitiesINPUT = Null; (* formRhoINPUT only works with the evolution system. The conservation *) (* laws being tested must be transformed to match the evolution system. *) formRhoINPUT = {}; (* d_kp2ddy.m *) (* end of file *)