19 Elliptic IntegralsSymmetric Integrals

§19.17 Graphics

See Figures 19.17.1–19.17.8 for symmetric elliptic integrals with real arguments.

Because the R-function is homogeneous, there is no loss of generality in giving one variable the value 1 or −1 (as in Figure 19.3.2). For RF, RG, and RJ, which are symmetric in x,y,z, we may further assume that z is the largest of x,y,z if the variables are real, then choose z=1, and consider only 0≤x≤1 and 0≤y≤1. The cases x=0 or y=0 correspond to the complete integrals. The case y=1 corresponds to elementary functions.

To view RF⁡(0,y,1) and 2⁢RG⁡(0,y,1) for complex y, put y=1−k2, use (19.25.1), and see Figures 19.3.7–19.3.12.

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Figure 19.17.1: RF⁡(x,y,1) for 0≤x≤1, y=0, 0.1, 0.5, 1. y=1 corresponds to RC⁡(x,1). Magnify
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Figure 19.17.2: RG⁡(x,y,1) for 0≤x≤1, y=0, 0.1, 0.5, 1. y=1 corresponds to 12⁢(RC⁡(x,1)+x). Magnify

To view RF⁡(0,y,1) and 2⁢RG⁡(0,y,1) for complex y, put y=1−k2, use (19.25.1), and see Figures 19.3.7–19.3.12.

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Figure 19.17.3: RD⁡(x,y,1) for 0≤x≤2, y=0, 0.1, 1, 5, 25. y=1 corresponds to 32⁢(RC⁡(x,1)−x)/(1−x), x≠1. Magnify
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Figure 19.17.4: RJ⁡(x,y,1,2) for 0≤x≤1, y=0, 0.1, 0.5, 1. y=1 corresponds to 3⁢(RC⁡(x,1)−RC⁡(x,2)). Magnify
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Figure 19.17.5: RJ⁡(x,y,1,0.5) for 0≤x≤1, y=0, 0.1, 0.5, 1. y=1 corresponds to 6⁢(RC⁡(x,0.5)−RC⁡(x,1)). Magnify
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Figure 19.17.6: Cauchy principal value of RJ⁡(x,y,1,−0.5) for 0≤x≤1, y=0, 0.1, 0.5, 1. y=1 corresponds to 2⁢(RC⁡(x,−0.5)−RC⁡(x,1)). Magnify
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Figure 19.17.7: Cauchy principal value of RJ⁡(0.5,y,1,p) for y=0, 0.01, 0.05, 0.2, 1, −1≤p<0. y=1 corresponds to 3⁢(RC⁡(0.5,p)−(π/8))/(1−p). As p→0 the curve for y=0 has the finite limit −8.10386⁢…; see (19.20.10). Magnify 3D Help
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Figure 19.17.8: RJ⁡(0,y,1,p), 0≤y≤1, −1≤p≤2. Cauchy principal values are shown when p<0. The function is asymptotic to 32⁢π/y⁢p as p→0+, and to (32/p)⁢ln⁡(16/y) as y→0+. As p→0− it has the limit (−6/y)⁢RG⁡(0,y,1). When p=1, it reduces to RD⁡(0,y,1). If y=1, then it has the value 32⁢π/(p+p) when p>0, and 32⁢π/(p−1) when p<0. See (19.20.10), (19.20.11), and (19.20.8) for the cases p→0±, y→0+, and y=1, respectively. Magnify 3D Help