Numeric error propagation: Difference between revisions
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m (→{{header|REXX}}: added whitespace, used a template for the output section.) |
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parse var ax ax '±' axe; parse var bx bx '±' bxE /* " err " Ax and Bx.*/ |
parse var ax ax '±' axe; parse var bx bx '±' bxE /* " err " Ax and Bx.*/ |
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parse var ay ay '±' aye; parse var by by '±' byE /* " " " Ay " By.*/ |
parse var ay ay '±' aye; parse var by by '±' byE /* " " " Ay " By.*/ |
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if axE=='' then axE=0; |
if axE=='' then axE= 0; if bxE=="" then bxE= 0 /*No error? Then use default.*/ |
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if ayE=='' then ayE=0; |
if ayE=='' then ayE= 0; if byE=="" then byE= 0 /* " " " " " */ |
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say ' A point (x,y)= ' ax "±" axE', ' ay "±" ayE |
say ' A point (x,y)= ' ax "±" axE', ' ay "±" ayE /*display A point (with err)*/ |
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say ' B point (x.y)= ' bx "±" bxE', ' by "±" byE |
say ' B point (x.y)= ' bx "±" bxE', ' by "±" byE /* " B " " " */ |
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say /*blank line for the eyeballs.*/ |
say /*blank line for the eyeballs.*/ |
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dx=ax-bx; dxE=sqrt(axE**2 + bxE**2); |
dx= ax-bx; dxE= sqrt(axE**2 + bxE**2); xe= #(dx, 2, dxE) /*compute X distances (& err)*/ |
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dy=ay-by; dyE=sqrt(ayE**2 + byE**2); |
dy= ay-by; dyE= sqrt(ayE**2 + byE**2); ye= #(dy, 2, dyE) /* " Y " " " */ |
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D=sqrt(dx**2 + dy**2) |
D= sqrt(dx**2 + dy**2) /*compute the 2D distance. */ |
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say 'distance=' D "±" #(D**2, .5, sqrt(xE**2 + yE**2)) /*display " " " */ |
say 'distance=' D "±" #(D**2, .5, sqrt(xE**2 + yE**2)) /*display " " " */ |
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exit |
exit 0 /*stick a fork in it, we're all done. */ |
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/*──────────────────────────────────────────────────────────────────────────────────────*/ |
/*──────────────────────────────────────────────────────────────────────────────────────*/ |
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#: procedure; arg x,p,e; if p=.5 then z=1/sqrt(abs(x)); else z=abs(x)**(p-1); return p*e*z |
#: procedure; arg x,p,e; if p=.5 then z=1/sqrt(abs(x)); else z=abs(x)**(p-1); return p*e*z |
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m.=9; do j=0 while h>9; m.j=h; h=h%2+1; end /*j*/ |
m.=9; do j=0 while h>9; m.j=h; h=h%2+1; end /*j*/ |
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do k=j+5 to 0 by -1; numeric digits m.k; g=(g+x/g)*.5; end /*k*/ |
do k=j+5 to 0 by -1; numeric digits m.k; g=(g+x/g)*.5; end /*k*/ |
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numeric digits d; return g/1 |
numeric digits d; return g/1 |
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/*──────────────────────────────────────────────────────────────────────────────────────*/ |
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sqrt: procedure; parse arg x; if x=0 then return 0; d=digits(); numeric digits; h=d+6 |
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numeric form; parse value format(x,2,1,,0) 'E0' with g "E" _ .; g= g * .5'e'_ % 2 |
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m.= 9; do j=0 while h>9; m.j= h; h= h%2+1; end /*j*/ |
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do k=j+5 to 0 by -1; numeric digits m.k; g= (g+x/g)*.5; end /*k*/ |
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numeric digits d; return g/1</lang> |
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<pre> |
<pre> |
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A point (x,y)= 100 ± 1.1, 50 ± 1.2 |
A point (x,y)= 100 ± 1.1, 50 ± 1.2 |
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