| General > General Technical Chat |
| What calculator do you use ? |
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| PA4TIM:
I tried my 35, 35s, 15C, 15C app they all agreed with the table Tried my 45 ipad app and 42S windowsPhone app and they do not agree. The 45 gives 9.000000000 The 42S gives 9.0000000004 |
| IanB:
Evidently computers may have an advantage over calculators. This is what my calculator program produces: > 180/pi * asin acos atan tan cos sin (9/180*pi) 9 > ans - 9 1.06581410364e-014 > Perhaps calculators these days should simply be based on an ordinary micro and do IEEE double precision arithmetic in binary? |
| IanB:
--- Quote from: IanB on November 18, 2012, 09:35:53 pm ---Evidently computers may have an advantage over calculators. This is what my calculator program produces: > 180/pi * asin acos atan tan cos sin (9/180*pi) 9 > ans - 9 1.06581410364e-014 > Perhaps calculators these days should simply be based on an ordinary micro and do IEEE double precision arithmetic in binary? --- End quote --- OK, not quite the right test. My program doesn't have a degrees mode. Here is keeping everything in degrees: > d=180/pi 57.2957795131 > r=pi/180 0.0174532925199 > d*asin(d*acos(d*atan(tan(r*cos(r*sin(r*9)))))) 8.99999999983 > Now the result is not quite so close. Maybe I need quadruple precision... |
| PA0PBZ:
The Windows 7 Calculator: asind(acosd(atand(tand(cosd(sind(9)))))) - 9 3.3055861301806391104645128745734e-32 Close enough 8) |
| rr100:
--- Quote from: IanB on November 18, 2012, 09:35:53 pm ---Evidently computers may have an advantage over calculators. This is what my calculator program produces: > 180/pi * asin acos atan tan cos sin (9/180*pi) 9 > ans - 9 1.06581410364e-014 > --- End quote --- 14-16-20 digits (or even much more) precision is nothing, even 64kB RAM devices should to that easily. This is what computers do: --- Code: ---> 180*arcsin(arccos(arctan(tan(cos(sin(9*Pi*(1/180)))))))/Pi; 9 > arccos(arctan(tan(cos(sin(9*Pi*(1/180)))))); Pi sin(----) 20 --- End code --- That's a 9 of course. With a (newish) Maple but I'm convinced even the V5 from 1997 would do the same. |
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