Where should I define JS function to call in EJS template

Just posting this answer here for someone who would might end up on this question while resolving same issue.

All you have to do is create new file (say functions.ejs) and include it in the .ejs file where you want to call that function. So, I have function like this in file named functions.ejs:

<%
getPriceChgArrow = function(value) {
    arrow_img_name = "";
    if (value < 0) {
        arrow_img_name = "arrow_down12x13.gif";
    }
    else {
        arrow_img_name = "arrow_up12x13.gif";
    }
    return arrow_img_name;
}
%>

Then include functions.ejs into the file you want to call function from. Say, I want to call this function in quote.ejs file. So, I would include it as follows:

<% include *file_path*/functions %> 

Just use this function at appropriate location in your ejs file from where you want to call it. For example:

<img src = "http:/some_url/<% getPriceChgArrow(data_point[0].value) %>" />

and you are all set. Hope this helps someone.