Continued fraction: Difference between revisions

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=={{header|RPL}}==

This task demonstrates how both global and local variables, arithmetic expressions and stack can be used together to build a compact and versatile piece of code.

{{works with|Halcyon Calc|4.2.7}}

{| class="wikitable"

! RPL code

! Comment

|-

|

≪

4 ROLL ROT → an bn

≪ 'N' STO 0 '''WHILE''' N 2 ≥ '''REPEAT'''

an + INV bn * EVAL

'N' 1 STO- '''END'''

an + / + EVAL

'N' PURGE

≫ ≫ ‘'''→CFRAC'''’ STO

|

'''→CFRAC''' ''( a0 aN b1 bN n -- x ) ''

Unstack an and bn

Loop from N to 2

Calculate nth fraction

Decrement counter

Calculate last fraction with b1 in stack, then add a0

Discard N variable - not mandatory but hygienic

|}

{{in}}

<pre>

1 2 1 1 100 →CFRAC

2 'N' 1 'N-1' 100 →CFRAC

3 6 1 '(2*N-1)^2' 1000 →CFRAC

1 1 1 1 100 →CFRAC

1 '2-MOD(N,2)' 1 1 100 →CFRAC

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{{out}}

<pre>

5: 1.41421356237

4: 2.71828182846

3: 3.14159265334

2: 1.61803398875

1: 1.73205080757