Graphing Calculator on Android produces wrong results ! (compared to web)

dsnz shared this problem 3 years ago
Not a Problem

if you run the design of the attached file you will get different results on web and on Android

on web the results are

Cf = 0.00593

AB = 24.09566

and they are correct

on Android the results are

Cf = 0.02892

AB = 24.04689

and they are wrong

this is serious because these are simple basic calculations and may have financial/other serious consequences for people who depend on them (some use the apps beyond education purposes, e.g. building/construction/topography etc.)


1. Android is Android P latest (Android One) and latest update of app

2. the attached ggb file has been produced by the web version, input data are with 2 decimal places, on Android I can't sign in and save/sync (this has been mentioned in forums more than one month now) and also I can't find an option to open a ggb file, the content is very simple that you can enter manually on Android app and test

Comments (5)


The easiest way to load on Android is using a link to the file eg


I don't see the bug with - what results do you see for that?



I followed your link and indeed it opened on Android, and even the text size became 16 pt as on web, and however I tried I got correct results ! Even if I started from a new state (by clearing everything) and inputting by hand I still get new results (remember this is a ggb exported from web).

As I was becoming crazy :) I remembered I had managed to save a .ggb locally on Android by the share option in my first attempts. It's a first edition code having only the Cf distance calculation and in that edition I worked with bigger numbers, where all X are plus 500 and all Y are plus 200 and later I removed the leading digit in order to simplify the numbers, but still the result should be the same (except for the line formula of course). I opened this file on Android and web and get wrong results in both, even if I delete a Point/Line/Distance and reenter it. So, it seems that it some calculation that gets stuck internally and affects the result and this has been captured internally in the ggb file.

Note: on web, after loading the Line and Distance formulas display first and then the rest. I don't know why, on Android they display in proper order (I managed to load the ggb on Android not from the menu but using a file manager and then selecting the Graphing Calculator from a list of apps to process it).

I hope you can replicate this and perhaps by examining the ggb file understand the issue.


I think you've just mis-typed the .32 / .23 here:

B = (62.32, 48.99)
B = (262.23, 548.99)


Yes !

I checked now and you are right. Never work at night with many calculations again !

I'm sorry for the wrong alert.

Thank you,

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