update n-body example

Author: kaikalii

examples/n-body.ua

@@ -3,7 +3,7 @@ Dt    ← 0.01
 Steps ← 120
 
 Step ← (
-  ⊞≠.⇡⧻.        # Make comparison matrix
+  ⊞≠.°⊏         # Make comparison matrix
   ⊃(≡▽⊙¤)⋅∘     # Make others
   ⊃≡(-¤)∘:      # Get diffs
   ÷⍜♭₂(≡/+×.).  # Inverse square
@@ -13,12 +13,12 @@ Step ← (
 )
 
 [0_60 150_0 30_15 80_110]
-⟜(↯:0⊂:2⧻) # Init vels
+⟜(↯⊙0⊂⊙2⧻) # Init vels
 
-⁅×0.5⇌[⊙◌⍥(Step ⟜:)Steps] # Run
-⍜⊙♭₂-¤/↧♭₂.               # Normalize
-⬚0≡(°⊚)                   # Plot
-≡(⧈(/↥/↥)3_3)             # Upscale
+⁅×0.5 ⍥⤚Step Steps # Run
+⍜⊙♭₂-¤/↧♭₂.        # Normalize
+⬚0≡(°⊚)            # Plot
+≡(⧈(/↥♭)3_3)       # Upscale
 
 &fwa "n-body.gif" gif 16
 &p "Wrote gif to n-body.gif"