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Production Manager’s Observation

Vector 12:1, page 106

mathematics and statistics implementations

Transcribed from the printed issue; not yet reviewed. Read it in the PDF of the issue, page 106

When run in Dyalog/W, the sample evaluations produce very slightly different results! Both are run in the same comparison tolerance!

First Example …

      ⎕CT←1E¯15
      R←CEI1¨ P←0,0.1×⍳9
      3 1 15 10 20 15⍕P,R,[1.5] R
0.0   1.5707963268   1.570796326794897
0.1   1.5747455615   1.574745561517356
0.2   1.5868678475   1.586867847454166
0.3   1.6080486199   1.608048619930513
0.4   1.6399998659   1.639999865864511
0.5   1.6857503548   1.685750354812596
0.6   1.7507538029   1.750753802915753
0.7   1.8456939984   1.845693998374724
0.8   1.9953027777   1.995302777664730
0.9   2.2805491384   2.280549138422770

Second Example …

      ⎕CT←1E¯15
      R←CEI2¨ P←0,.1×⍳10
      3 1 15 10 20 15⍕P,R,[1.5] R
0.0   1.5707963268   1.570796326794897
0.1   1.5668619420   1.566861942021668
0.2   1.5549685462   1.554968546242529
0.3   1.5348334649   1.534833464923250
0.4   1.5059416124   1.505941612360040
0.5   1.4674622093   1.467462209339424
0.6   1.4180833944   1.418083394448724
0.7   1.3556611356   1.355661135571955
0.8   1.2763499432   1.276349943169906
0.9   1.1716970528   1.171697052781616
1.0   1.0000000000   1.000000000000000

Perhaps someone with Mathematica could say which is correct!!