# Question:How to map an expression to x-axis and another expression to y-axis to a 2-D plot

## Question:How to map an expression to x-axis and another expression to y-axis to a 2-D plot

Maple 2019

Hello there,

Would you allow me to ask this question?

What I tried in the worksheet below is to map an expression to x-axis and another expression to y-axis, while both expressions have the same input (or independent variable). However, the resulting plot still shows those two expressions as two separate curves. Would you tell me how to map or assign the expressions to each axis?

 > restart;
 > with(LinearAlgebra):
 > Digits := 6:
 > j := I:
 > L__adpu := 1.66; L__aqpu := 1.61; L__lpu := 0.15; R__apu := 0.003; E__tpu := 1.0; MVA := 555;
 (1)
 > A__sat := 0.0312500: B__sat := 6.93147:
 > I__tpu_compare := (P__t - j* Q__t) / E__tpu;
 (2)
 > I__tpu_a := abs(I__tpu_compare);
 (3)
 > Phi := arccos(P__t / (I__tpu_a * E__tpu));
 (4)
 > E__a__tilde := E__tpu + (R__apu + j * L__lpu) * I__tpu_compare;
 (5)
 > psi__at := abs(E__a__tilde);
 (6)
 > psi__I := A__sat * exp(B__sat * (psi__at - 0.8));
 (7)
 > K__sd := psi__at / (psi__at + psi__I);
 (8)
 > K__sq := K__sd;
 (9)
 > X__d := X__ad + L__lpu:
 > X__aq := K__sq * L__aqpu:
 > X__q := X__aq + L__lpu:
 > delta__i := arctan((X__q * I__tpu_a * cos(Phi) - R__apu * I__tpu_a * sin(Phi))/(E__tpu + R__apu * I__tpu_a * cos(Phi) + X__q * I__tpu_a * sin(Phi))):
 > e__q := E__tpu * cos(delta__i):
 > i__d := I__tpu_a * sin(delta__i + Phi):
 > i__q := I__tpu_a * cos(delta__i + Phi):
 > i__fd := (e__q + R__apu * i__q + X__d * i__d)/(X__ad):
 > i_armature := sqrt(i__d^2 + i__q^2):
 > i_armature2 := subs(P__t = 0, i_armature):
 > i_armature3 := subs(P__t = 0.5, i_armature):
 > i_armature4 := subs(P__t = 1.0, i_armature):
 > plotA := plot(i_armature2, Q__t = -0.6..0.6):
 > plotB := plot(i_armature3, Q__t = -0.6..0.6):
 > plotC := plot(i_armature4, Q__t = -0.6..0.6):
 > plots:-display([plotA, plotB, plotC]);
 > i__fd2 := subs(P__t = 0, i__fd):
 > i__fd3 := subs(P__t = 0.5, i__fd):
 > i__fd4 := subs(P__t = 1.0, i__fd):
 >
 > plotD := plot(i__fd2, Q__t = -0.6..0.6):
 > plotE := plot(i__fd3, Q__t = -0.6..0.6):
 > plotF := plot(i__fd4, Q__t = -0.6..0.6):
 > plots:-display([plotD, plotE, plotF]);
 > plot([i__fd2, i_armature2, Q__t = -0.6..0.6]); #failed, two expressions are plotted seperately.
 >
 >

Best Regards,

In Kwon Park