Fonction math ^

[Stephane_Ferratfiat]

hello everyone, I can't seem to input this formula with APP's MATH functions:

= 100 ^ - ((F1-F2) / 5)

I thank you in advance for your help

cordially

Stephane

[Salman_Dev]

@Stephane_Ferratfiat

I can't seem to input this formula with APP's MATH functions:

See this example :

[TIMAI2]

or perhaps?....

[Juan_Antonio]

Also
100 ^ ((F2-F1) / 5)

[Stephane_Ferratfiat]

Merci pour votre réponse, cependant cela ne me donne pas la bonne réponse : cela me retourne 0.39811
Il s'agit d'une équation pour le calcul de magnitude
A la base l'equation est : M1-M2 = -2.5 log(F1/F2) => si F1=2 et F2=3, avec un écart de 1 le résultat et 2.51

Je continu à chercher, pourtant cela me semble simple car cela marche avec excel
Stéphane

[Stephane_Ferratfiat]

Merci pour votre réponse, cependant cela ne me donne pas la bonne réponse : cela me retourne 10
Il s'agit d'une équation pour le calcul de magnitude
A la base l'equation est : M1-M2 = -2.5 log(F1/F2) => si F1=2 et F2=3, avec un écart de 1 le résultat et 2.51

Je continu à chercher, pourtant cela me semble simple car cela marche avec excel

Stéphane

[Juan_Antonio]

Be careful with the logarithm, in App Inventor "log" is natural logarithm.

log10(X) = logN(X) / 2.3026

In the expression you are using, "log" is logarithm to base 10

Related:
https://www.chegg.com/homework-help/questions-and-answers/starting-formal-definition-apparent-magnitudes-f2-f1-100-m1-m2-5-definition-absolute-magni-q68166529

http://obswww.unige.ch/Questions_Reponses/R7.html

[TIMAI2]

@Stephane_Ferratfiat

M1-M2 = -2.5 log(F1/F2) => si F1=2 et F2=3

Like this ?

[Stephane_Ferratfiat]

Hello TIMAI2

which math extension are you using for your example?
I can't find in my blocks

thank you

Stéphane

[TIMAI2]

It may be that I have used external inputs from the right click menu

[Stephane_Ferratfiat]

Hello

thank you for your intervention.

I built the calculation block which should correspond to the mathematical function it does not give the same result!
I keep looking, yet it should be easy to do !!!

Stephane

[TIMAI2]

If you meant this

there is no extension, this is a built procedure using default blocks

[Stephane_Ferratfiat]

Hello

thank you for your intervention.

With excel I use:
X = 100 ^ - ((F1-F2) / 5)
If F1 = 2 and F3 = 3
X = 2.5119

I'll find it !!

Stéphane

[TIMAI2]

Well, these blocks are what i provided a few posts before, and they return that result.....

[Stephane_Ferratfiat]

Thank you it's Ok

I had to reverse an operator in the assembly of the block.
In the meantime, I have found another solution, but yours seems more conventional to me

I am new to the use of the app I discover its philosophy
This will be used for a calculator for astronomy calculations

thank you for everything

Stephane
Capture3|690x86

[Stephane_Ferratfiat]

[Stephane_Ferratfiat]

With your solution

Stephane