Introduction to Partial Differential Equations
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Chapter 2
Figure 2.1. Stationary wave — page 16
Figure 2.3. Traveling wave with c > 0 — page 20
Figure 2.5. Decaying traveling wave — page 22
Figure 2.8. Solution to ut + ux / (x2 + 1) = 0 — page 27
Figure 2.10. Solution to ut + (x2 - 1) ux = 0 — page 29
Figure 2.11. Two solutions to ut + u ux = 0 — page 33
Figure 2.14. Rarefaction wave — page 35
Figure 2.15. Multiply-valued compression wave — page 36
Figure 2.17. Multiply-valued step wave — page 40
Figure 2.20. Rarefaction wave — page 43
Figure 2.21. Equal Area Rule for the triangular wave — page 44
Multiply-valued solution
Equal area rule
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Figure 2.22. Triangular-wave solution — page 45
Figure 2.24. Splitting of waves — page 53
Figure 2.25. Interaction of waves — page 54
Equation (2.84): Particles and waves — page 55
The wave solution u(t,x) = cos t sin x = (sin(x-t) + sin(x+t))/2
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Constitutent traveling waves (particles)
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Particles and Waves
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Figure 2.27. Error function solution to the wave equation — page 56
Example 2.19. Forcing and resonance — page 59
Periodic solution
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Quasiperiodic solution
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Resonant solution
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Chapter 4
Figure 4.1. A solution to the heat equation — page 127
Figure 4.2. Denoising a signal with the heat equation — page 128
Slow time scale
Faster time scale
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Heat equation with periodic boundary conditions — pages 130-131
Figure 4.3. Plucked string solution of the wave equation — page 143
Dirichlet boundary conditions
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Neumann boundary conditions
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Figure 4.6. Solution to wave equation with fixed ends — page 148
Odd periodic extension of preceding solution
Chapter 5
Figure 5.2. Numerical solutions for the heat equation based on the explicit scheme — page 189
Δx = .1 Δt = .01 μ = 1.0
Δx = .1 Δt = .005 μ = .5
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Δx = .01 Δt = .0001 μ = 1.0
Δx = .01 Δt = .00005 μ = .5
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Figure 5.3. Numerical solutions for the heat equation based on the implicit scheme — page 191
Δx = .1 Δt = .01 μ = 1.0
Δx = .01 Δt = .01 μ = 100.
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Figure 5.4. Numerical Solutions for the heat equation based on the Crank-Nicolson scheme — page 192
Δx = .1 Δt = .01 μ = 1.0
Δx = .01 Δt = .01 μ = 100.
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Figure 5.5. Numerical solutions to the transport equation — page 196
Δx = Δt = .0005 c = σ = .5
Δx = Δt = .0005 c = σ = -.5
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Δx = Δt = .0005 c = σ = -1
Δx = Δt = .0005 c = σ = -1.5
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Figure 5.8. Centered difference numerical solution to the transport equation — page 200
Δx = Δt = .0005 c = σ = .5
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Figures 5.9 and 5.10. Numerically stable and unstable waves — page 204
c = 1.0 Δx = Δt = .01 σ = 1.0
c = 1.0 Δx = .01 Δt = .02 σ = 1.8
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c = 1.0 Δx = .0111111 Δt = .01 σ = .9
c = 1.0 Δx = .0090909 Δt = .01 σ = 1.1
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Chapter 8
Figure 8.1. The fundamental solution to the one-dimensional heat equation — page 294
Figure 8.2. Error function solution to the heat equation — page 296
Figure 8.3. Effect of a concentrated heat source — page 299
Figure 8.4. Solution to the Black-Scholes equation — page 302
Figure 8.5. Traveling-wave solutions to Burgers' equation — page 317
Figure 8.6. Trignometric solution to Burgers' equation — page 319
Figure 8.7. Shock-wave solution to Burgers' equation — page 321
Figure 8.8. Triangular-wave solution to Burgers' equation — page 322
Figure 8.9. Gaussian solution to the dispersive wave equation — page 325
Figure 8.10. Fundamental solution to the dispersive wave equation — page 327
Figure 8.11. Periodic dispersion at irrational (with respect to π) times — page 328
Figure 8.12. Periodic dispersion at rational (with respect to π) times — page 329
Figure 8.13. Solitary wave/soliton — page 334
Figure 8.14. Interaction of two solitons — page 335
Interaction of three solitons — page 336
Chapter 11
Figure 11.2. Heat diffusion in a rectangle — page 448
Figure 11.7. Heat diffusion in a disk — page 478
Figure 11.8. Fundamental solution of the planar heat equation — page 483
Figure 11.9. Diffusion of a disk — page 484
Figure 11.10. Vibrations of a square — page 489
Figure 11.11. Vibrations of a disk — page 491
Chapter 12
Figure 12.10. Wave equation solution u(t,r) due to an initial velocity of the unit ball — page 557
Figure 12.11. Wave equation solution u(t,r) due to an initial displacement of the unit ball — page 559
Figure 12.12. Solution to the two-dimensional wave equation for a concentrated impulse — page 563