Another update from ingydotnet^djgoku

Task/Euler-method/BASIC/euler-method-1.basic

@@ -0,0 +1,15 @@
+      PROCeuler("-0.07*(y-20)", 100, 0, 100, 2)
+      PROCeuler("-0.07*(y-20)", 100, 0, 100, 5)
+      PROCeuler("-0.07*(y-20)", 100, 0, 100, 10)
+      END
+
+      DEF PROCeuler(df$, y, a, b, s)
+      LOCAL t, @%
+      @% = &2030A
+      t = a
+      WHILE t <= b
+        PRINT t, y
+        y += s * EVAL(df$)
+        t += s
+      ENDWHILE
+      ENDPROC

Task/Euler-method/BASIC/euler-method-2.basic

@@ -0,0 +1,24 @@
+'Freebasic .9
+'Custom rounding
+#define round(x,N) Rtrim(Rtrim(Left(Str((x)+(.5*Sgn((x)))/(10^(N))),Instr(Str((x)+(.5*Sgn((x)))/(10^(N))),".")+(N)),"0"),".")
+
+#macro Euler(fn,_y,min,max,h,printoption)
+Print "Step ";#h;":":Print
+Print "time","Euler"," Analytic"
+If printoption<>"print" Then Print "Data omitted ..."
+Scope
+    Dim As Double temp=(min),y=(_y)
+    Do
+        If printoption="print" Then Print temp,round(y,3),20+80*Exp(-0.07*temp)
+        y=y+(h)*(fn)
+        temp=temp+(h)
+    Loop Until temp>(max)
+    Print"________________"
+    Print
+End Scope
+#endmacro
+
+Euler(-.07*(y-20),100,0,100,2,"don't print")
+Euler(-.07*(y-20),100,0,100,5,"print")
+Euler(-.07*(y-20),100,0,100,10,"print")
+Sleep

Task/Euler-method/BASIC/euler-method-3.basic

@@ -0,0 +1,14 @@
+x = euler(-0.07,-20, 100, 0, 100, 2)
+x = euler-0.07,-20, 100, 0, 100, 5)
+x = euler(-0.07,-20, 100, 0, 100, 10)
+end
+
+FUNCTION euler(da,db, y, a, b, s)
+print "===== da:";da;" db:";db;" y:";y;" a:";a;" b:";b;" s:";s;" ==================="
+t = a
+WHILE t <= b
+   PRINT t;chr$(9);y
+   y = y + s * (da * (y + db))
+   t = t + s
+WEND
+END FUNCTION