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Numeric error propagation: Difference between revisions

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Numeric error propagation (view source)

Revision as of 15:43, 14 March 2022

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→‎{{header|Phix}}: syntax coloured
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=={{header|Phix}}==
<!--<lang Phix>enum VALUE, DELTA(phixonline)-->
<span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
 
<span style="color: #008080;">enum</span> <span style="color: #000000;">VALUE</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">DELTA</span>
type imprecise(object imp)
return sequence(imp) and atom(imp[VALUE]) and atom(imp[DELTA])
<span style="color: #008080;">type</span> <span style="color: #000000;">imprecise</span><span style="color: #0000FF;">(</span><span style="color: #004080;">object</span> <span style="color: #000000;">imp</span><span style="color: #0000FF;">)</span>
end type
<span style="color: #008080;">return</span> <span style="color: #004080;">sequence</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imp</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">and</span> <span style="color: #004080;">atom</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imp</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">])</span> <span style="color: #008080;">and</span> <span style="color: #004080;">atom</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imp</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">])</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">type</span>
function sqr(atom a)
return a*a
<span style="color: #008080;">function</span> <span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #004080;">atom</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">)</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">*</span><span style="color: #000000;">a</span>
 
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function imprecise_add(imprecise a, b)
atom delta = sqrt(sqr(a[DELTA]) + sqr(b[DELTA]))
<span style="color: #008080;">function</span> <span style="color: #000000;">imprecise_add</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imprecise</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">)</span>
imprecise ret = {a[VALUE] + b[VALUE], delta}
<span style="color: #004080;">atom</span> <span style="color: #000000;">delta</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sqrt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">])</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">]))</span>
return ret
<span style="color: #000000;">imprecise</span> <span style="color: #000000;">ret</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">delta</span><span style="color: #0000FF;">}</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">ret</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function imprecise_mul(imprecise a, b)
atom delta = sqrt(sqr(a[VALUE]*b[DELTA]) + sqr(b[VALUE]*a[DELTA]))
<span style="color: #008080;">function</span> <span style="color: #000000;">imprecise_mul</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imprecise</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">)</span>
imprecise ret = {a[VALUE] * b[VALUE],delta}
<span style="color: #004080;">atom</span> <span style="color: #000000;">delta</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sqrt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">]*</span><span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">])</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">]*</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">]))</span>
return ret
<span style="color: #000000;">imprecise</span> <span style="color: #000000;">ret</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">*</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">],</span><span style="color: #000000;">delta</span><span style="color: #0000FF;">}</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">ret</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function imprecise_div(imprecise a, b)
atom delta = sqrt(sqr(a[VALUE]*b[DELTA]) + sqr(b[VALUE]*a[DELTA]))/sqr(b[VALUE])
<span style="color: #008080;">function</span> <span style="color: #000000;">imprecise_div</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imprecise</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">)</span>
imprecise ret = {a[VALUE] / b[VALUE], delta}
<span style="color: #004080;">atom</span> <span style="color: #000000;">delta</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">sqrt</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">]*</span><span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">])</span> <span style="color: #0000FF;">+</span> <span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">]*</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">]))/</span><span style="color: #000000;">sqr</span><span style="color: #0000FF;">(</span><span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">])</span>
return ret
<span style="color: #000000;">imprecise</span> <span style="color: #000000;">ret</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">/</span> <span style="color: #000000;">b</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">delta</span><span style="color: #0000FF;">}</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">ret</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function imprecise_pow(imprecise a, atom c)
atom v = power(a[VALUE], c),
<span style="color: #008080;">function</span> <span style="color: #000000;">imprecise_pow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imprecise</span> <span style="color: #000000;">a</span><span style="color: #0000FF;">,</span> <span style="color: #004080;">atom</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">)</span>
delta = abs(v*c*a[DELTA]/a[VALUE])
<span style="color: #004080;">atom</span> <span style="color: #000000;">v</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">power</span><span style="color: #0000FF;">(</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">],</span> <span style="color: #000000;">c</span><span style="color: #0000FF;">),</span>
imprecise ret = {v,delta}
<span style="color: #000000;">delta</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">abs</span><span style="color: #0000FF;">(</span><span style="color: #000000;">v</span><span style="color: #0000FF;">*</span><span style="color: #000000;">c</span><span style="color: #0000FF;">*</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">DELTA</span><span style="color: #0000FF;">]/</span><span style="color: #000000;">a</span><span style="color: #0000FF;">[</span><span style="color: #000000;">VALUE</span><span style="color: #0000FF;">])</span>
return ret
<span style="color: #000000;">imprecise</span> <span style="color: #000000;">ret</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">v</span><span style="color: #0000FF;">,</span><span style="color: #000000;">delta</span><span style="color: #0000FF;">}</span>
end function
<span style="color: #008080;">return</span> <span style="color: #000000;">ret</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
function printImprecise(imprecise imp)
return sprintf("%g+/-%g",imp)
<span style="color: #008080;">function</span> <span style="color: #000000;">printImprecise</span><span style="color: #0000FF;">(</span><span style="color: #000000;">imprecise</span> <span style="color: #000000;">imp</span><span style="color: #0000FF;">)</span>
end function
<span style="color: #008080;">return</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%g+/-%g"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">imp</span><span style="color: #0000FF;">)</span>
<span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
imprecise x1 = {100, 1.1},
y1 = {50, 1.2},
<span style="color: #000000;">imprecise</span> <span style="color: #000000;">x1</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">100</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1.1</span><span style="color: #0000FF;">},</span>
x2 = {-200, 2.2},
<span style="color: #000000;">y1</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">50</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">1.2</span><span style="color: #0000FF;">},</span>
y2 = {-100, 2.3},
<span style="color: #000000;">x2</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{-</span><span style="color: #000000;">200</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">2.2</span><span style="color: #0000FF;">},</span>
tmp1, tmp2,
<span style="color: #000000;">y2</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{-</span><span style="color: #000000;">100</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">2.3</span><span style="color: #0000FF;">},</span>
d
<span style="color: #000000;">tmp1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">tmp2</span><span style="color: #0000FF;">,</span>
<span style="color: #000000;">d</span>
tmp1 = imprecise_add(x1, x2)
tmp1 = imprecise_pow(tmp1, 2)
<span style="color: #000000;">tmp1</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">imprecise_add</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">x2</span><span style="color: #0000FF;">)</span>
tmp2 = imprecise_add(y1, y2)
<span style="color: #000000;">tmp1</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">imprecise_pow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">tmp1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
tmp2 = imprecise_pow(tmp2, 2)
<span style="color: #000000;">tmp2</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">imprecise_add</span><span style="color: #0000FF;">(</span><span style="color: #000000;">y1</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">y2</span><span style="color: #0000FF;">)</span>
d = imprecise_add(tmp1,tmp2)
<span style="color: #000000;">tmp2</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">imprecise_pow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">tmp2</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">2</span><span style="color: #0000FF;">)</span>
d = imprecise_pow(d, 0.5)
<span style="color: #000000;">d</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">imprecise_add</span><span style="color: #0000FF;">(</span><span style="color: #000000;">tmp1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">tmp2</span><span style="color: #0000FF;">)</span>
printf(1,"Distance, d, between the following points :")
<span style="color: #000000;">d</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">imprecise_pow</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d</span><span style="color: #0000FF;">,</span> <span style="color: #000000;">0.5</span><span style="color: #0000FF;">)</span>
printf(1,"\n( x1, y1) = ( %s, %s)",{printImprecise(x1),printImprecise(y1)})
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"Distance, d, between the following points :"</span><span style="color: #0000FF;">)</span>
printf(1,"\n( x2, y2) = ( %s, %s)",{printImprecise(x2),printImprecise(y2)})
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n( x1, y1) = ( %s, %s)"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">printImprecise</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x1</span><span style="color: #0000FF;">),</span><span style="color: #000000;">printImprecise</span><span style="color: #0000FF;">(</span><span style="color: #000000;">y1</span><span style="color: #0000FF;">)})</span>
printf(1,"\nis d = %s\n", {printImprecise(d)})</lang>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\n( x2, y2) = ( %s, %s)"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">printImprecise</span><span style="color: #0000FF;">(</span><span style="color: #000000;">x2</span><span style="color: #0000FF;">),</span><span style="color: #000000;">printImprecise</span><span style="color: #0000FF;">(</span><span style="color: #000000;">y2</span><span style="color: #0000FF;">)})</span>
<span style="color: #7060A8;">printf</span><span style="color: #0000FF;">(</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #008000;">"\nis d = %s\n"</span><span style="color: #0000FF;">,</span> <span style="color: #0000FF;">{</span><span style="color: #000000;">printImprecise</span><span style="color: #0000FF;">(</span><span style="color: #000000;">d</span><span style="color: #0000FF;">)})</span>
<!--</lang>-->
Aside: obviously you don't ''have'' to use tmp1/2 like that, but I find that style often makes things much easier to debug.
{{out}}
Petelomax
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