max and superscript problems in equation

Question

I need to display this equation:

But I keep getting the following:

I do not know how to make the subscript in the max function and the superscript to end.
Here is my code:
begin{equation*}

Q(s,a) leftarrow Q(s,a)+alpha left( r+ gamma max_{{a^'}in{A}} Q(s^',a^')-Q(s,a)right)

end{equation*}

Bernard · Accepted Answer

Use this much simpler code, and you'll have no problem. Note it's better to  control the size of the parentheses here  with the pair Bigl( … Bigr) rather than left( … right).
begin{equation*}
Q(s,a) leftarrow Q(s,a)+alpha Bigl( r+ gamma max_{a' in A } Q(s',a') - Q(s,a)Bigr)
end{equation*}

Gnoppi · Answer

Try this:
Q(s,a) leftarrow Q(s,a) + alpha Big ( r + gamma mathop{text{max}}_{a' in A} Q(s',a') - Q(s,a) Big )

Tanvir · Answer

Use limits to put some text or math below max
Here is the code which you can try
documentclass{article}
usepackage{amsmath}

begin{document}

begin{align*} 
Q(s,a) leftarrow Q(s,a)+alpha,left(r+ gamma maxlimits_{a',in, A},Q(s',a')-Q(s,a)right)
end{align*}

end{document}

Willie Wong · Answer

The most important protip for using LaTeX:

When your compiler shows you errors: read the errors and try to resolve them.

The reason that your code generated odd output is because LaTeX encountered an error in your code and did its best to guess what you meant. Frequently the guess is wrong, and so you get the wrong output.
Now, to the error: your compilation should've shown something like
l.5 ...w Q(s,a)+alpha left( r+ gamma max_{{a^'
                                                  }in{A}} Q(s^',a^')-Q(s,a)r...

this tells you that when LaTeX read up to the prime sign ' it encountered an error. The error is because that the sign ' is already in superscript mode when used in mathematics. If you try to put ^' this is a double superscript and causes an error.
So all you need to do is to remove the doubling. Instead of a^', type a' and this will give you the correct output.

max and superscript problems in equation

4 Answers

Add your own answers!

Ask a Question