Polynomial derivative: Difference between revisions

Line 192:

Derivative of x3-2x2+3x-4: 3 - 4*x + 3*x^2

Derivative of -x4-x3+x+1: 1 - 3*x^2 - 4*x^3

</pre>

=={{header|Phix}}==

--

-- demo\rosetta\Polynomial_derivative.exw

--

with javascript_semantics

function derivative(sequence p)

if p={} then return {} end if

sequence r = repeat(0,length(p)-1)

for i=1 to length(r) do

r[i] = i*p[i+1]

end for

return r

end function

function poly(sequence si)

-- display helper, copied from demo\rosetta\Polynomial_long_division.exw

string r = ""

for t=length(si) to 1 by -1 do

integer sit = si[t]

if sit!=0 then

if sit=1 and t>1 then

r &= iff(r=""? "":" + ")

elsif sit=-1 and t>1 then

r &= iff(r=""?"-":" - ")

else

if r!="" then

r &= iff(sit<0?" - ":" + ")

sit = abs(sit)

end if

r &= sprintf("%d",sit)

end if

r &= iff(t>1?"x"&iff(t>2?sprintf("^%d",t-1):""):"")

end if

end for

if r="" then r="0" end if

return r

end function

constant tests = {{5},{4,-3},{-1,6,5},{-4,3,-2,1},{1,1,0,-1,-1}}

for i=1 to length(tests) do

sequence t = tests[i],

r = derivative(t)

printf(1,"%20s ==> %16s (internally %V -> %V)\n",{poly(t),poly(r),t,r})

end for

?"done"

{} = wait_key()

<pre>

5 ==> 0 (internally {5} -> {})

-3x + 4 ==> -3 (internally {4,-3} -> {-3})

5x^2 + 6x - 1 ==> 10x + 6 (internally {-1,6,5} -> {6,10})

x^3 - 2x^2 + 3x - 4 ==> 3x^2 - 4x + 3 (internally {-4,3,-2,1} -> {3,-4,3})

-x^4 - x^3 + x + 1 ==> -4x^3 - 3x^2 + 1 (internally {1,1,0,-1,-1} -> {1,0,-3,-4})

</pre>

@@ Line 192: / Line 192: @@
 Derivative of x3-2x2+3x-4: 3 - 4*x + 3*x^2
 Derivative of -x4-x3+x+1: 1 - 3*x^2 - 4*x^3
+</pre>
+=={{header|Phix}}==
+<!--<lang Phix>(phixonline)-->
+ <span style="color: #000080;font-style:italic;">--
+ -- demo\rosetta\Polynomial_derivative.exw
+ --</span>
+ <span style="color: #008080;">with</span> <span style="color: #008080;">javascript_semantics</span>
+ <span style="color: #008080;">function</span> <span style="color: #000000;">derivative</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">p</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">if</span> <span style="color: #000000;">p</span><span style="color: #0000FF;">={}</span> <span style="color: #008080;">then</span> <span style="color: #008080;">return</span> <span style="color: #0000FF;">{}</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+     <span style="color: #004080;">sequence</span> <span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">repeat</span><span style="color: #0000FF;">(</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">p</span><span style="color: #0000FF;">)-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">)</span>
+     <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">r</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
+         <span style="color: #000000;">r</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">]</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">*</span><span style="color: #000000;">p</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">+</span><span style="color: #000000;">1</span><span style="color: #0000FF;">]</span>
+     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
+     <span style="color: #008080;">return</span> <span style="color: #000000;">r</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
+ <span style="color: #008080;">function</span> <span style="color: #000000;">poly</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">si</span><span style="color: #0000FF;">)</span>
+ <span style="color: #000080;font-style:italic;">-- display helper, copied from demo\rosetta\Polynomial_long_division.exw</span>
+     <span style="color: #004080;">string</span> <span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #008000;">""</span>
+     <span style="color: #008080;">for</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">=</span><span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">si</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">to</span> <span style="color: #000000;">1</span> <span style="color: #008080;">by</span> <span style="color: #0000FF;">-</span><span style="color: #000000;">1</span> <span style="color: #008080;">do</span>
+         <span style="color: #004080;">integer</span> <span style="color: #000000;">sit</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">si</span><span style="color: #0000FF;">[</span><span style="color: #000000;">t</span><span style="color: #0000FF;">]</span>
+         <span style="color: #008080;">if</span> <span style="color: #000000;">sit</span><span style="color: #0000FF;">!=</span><span style="color: #000000;">0</span> <span style="color: #008080;">then</span>
+             <span style="color: #008080;">if</span> <span style="color: #000000;">sit</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">and</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">></span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
+                 <span style="color: #000000;">r</span> <span style="color: #0000FF;">&=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">r</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span><span style="color: #0000FF;">?</span> <span style="color: #008000;">""</span><span style="color: #0000FF;">:</span><span style="color: #008000;">" + "</span><span style="color: #0000FF;">)</span>
+             <span style="color: #008080;">elsif</span> <span style="color: #000000;">sit</span><span style="color: #0000FF;">=-</span><span style="color: #000000;">1</span> <span style="color: #008080;">and</span> <span style="color: #000000;">t</span><span style="color: #0000FF;">></span><span style="color: #000000;">1</span> <span style="color: #008080;">then</span>
+                 <span style="color: #000000;">r</span> <span style="color: #0000FF;">&=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">r</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span><span style="color: #0000FF;">?</span><span style="color: #008000;">"-"</span><span style="color: #0000FF;">:</span><span style="color: #008000;">" - "</span><span style="color: #0000FF;">)</span>
+             <span style="color: #008080;">else</span>
+                 <span style="color: #008080;">if</span> <span style="color: #000000;">r</span><span style="color: #0000FF;">!=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span>
+                     <span style="color: #000000;">r</span> <span style="color: #0000FF;">&=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sit</span><span style="color: #0000FF;"><</span><span style="color: #000000;">0</span><span style="color: #0000FF;">?</span><span style="color: #008000;">" - "</span><span style="color: #0000FF;">:</span><span style="color: #008000;">" + "</span><span style="color: #0000FF;">)</span>
+                     <span style="color: #000000;">sit</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">abs</span><span style="color: #0000FF;">(</span><span style="color: #000000;">sit</span><span style="color: #0000FF;">)</span>
+                 <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+                 <span style="color: #000000;">r</span> <span style="color: #0000FF;">&=</span> <span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"%d"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">sit</span><span style="color: #0000FF;">)</span>
+             <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+             <span style="color: #000000;">r</span> <span style="color: #0000FF;">&=</span> <span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">></span><span style="color: #000000;">1</span><span style="color: #0000FF;">?</span><span style="color: #008000;">"x"</span><span style="color: #0000FF;">&</span><span style="color: #008080;">iff</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">></span><span style="color: #000000;">2</span><span style="color: #0000FF;">?</span><span style="color: #7060A8;">sprintf</span><span style="color: #0000FF;">(</span><span style="color: #008000;">"^%d"</span><span style="color: #0000FF;">,</span><span style="color: #000000;">t</span><span style="color: #0000FF;">-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">):</span><span style="color: #008000;">""</span><span style="color: #0000FF;">):</span><span style="color: #008000;">""</span><span style="color: #0000FF;">)</span>
+         <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+     <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
+     <span style="color: #008080;">if</span> <span style="color: #000000;">r</span><span style="color: #0000FF;">=</span><span style="color: #008000;">""</span> <span style="color: #008080;">then</span> <span style="color: #000000;">r</span><span style="color: #0000FF;">=</span><span style="color: #008000;">"0"</span> <span style="color: #008080;">end</span> <span style="color: #008080;">if</span>
+     <span style="color: #008080;">return</span> <span style="color: #000000;">r</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">function</span>
+ <span style="color: #008080;">constant</span> <span style="color: #000000;">tests</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{{</span><span style="color: #000000;">5</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">3</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">,</span><span style="color: #000000;">5</span><span style="color: #0000FF;">},{-</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">0</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,-</span><span style="color: #000000;">1</span><span style="color: #0000FF;">}}</span>
+ <span style="color: #008080;">for</span> <span style="color: #000000;">i</span><span style="color: #0000FF;">=</span><span style="color: #000000;">1</span> <span style="color: #008080;">to</span> <span style="color: #7060A8;">length</span><span style="color: #0000FF;">(</span><span style="color: #000000;">tests</span><span style="color: #0000FF;">)</span> <span style="color: #008080;">do</span>
+     <span style="color: #004080;">sequence</span> <span style="color: #000000;">t</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">tests</span><span style="color: #0000FF;">[</span><span style="color: #000000;">i</span><span style="color: #0000FF;">],</span>
+              <span style="color: #000000;">r</span> <span style="color: #0000FF;">=</span> <span style="color: #000000;">derivative</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</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;">"%20s ==&gt; %16s   (internally %V -&gt; %V)\n"</span><span style="color: #0000FF;">,{</span><span style="color: #000000;">poly</span><span style="color: #0000FF;">(</span><span style="color: #000000;">t</span><span style="color: #0000FF;">),</span><span style="color: #000000;">poly</span><span style="color: #0000FF;">(</span><span style="color: #000000;">r</span><span style="color: #0000FF;">),</span><span style="color: #000000;">t</span><span style="color: #0000FF;">,</span><span style="color: #000000;">r</span><span style="color: #0000FF;">})</span>
+ <span style="color: #008080;">end</span> <span style="color: #008080;">for</span>
+ <span style="color: #0000FF;">?</span><span style="color: #008000;">"done"</span>
+ <span style="color: #0000FF;">{}</span> <span style="color: #0000FF;">=</span> <span style="color: #7060A8;">wait_key</span><span style="color: #0000FF;">()</span>
+<!--</lang>-->
+{{out}}
+<pre>
+==>                0   (internally {5} -> {})
+             -3x + 4 ==>               -3   (internally {4,-3} -> {-3})
+x^2 + 6x - 1 ==>          10x + 6   (internally {-1,6,5} -> {6,10})
+ x^3 - 2x^2 + 3x - 4 ==>    3x^2 - 4x + 3   (internally {-4,3,-2,1} -> {3,-4,3})
+  -x^4 - x^3 + x + 1 ==> -4x^3 - 3x^2 + 1   (internally {1,1,0,-1,-1} -> {1,0,-3,-4})
 </pre>