today I continue writing notes about measuring quality of learning. You can read my previuos artcile 1 and article 2 about measures of quality of learning. If to summarize two of those articles we have the following:
accuracy is good measure, but if samplings is unbalanced then accuracy can have great numbers, but total model will be very bad.
precision tells you how objects model a(x) can find
precision and recall work fine on unbalanced samplings
And then question arises, is it possible somehow to merge them, but not as accuracy but as something more meaningful then accuracy?
I'll decribe different ways to describe it going from worsest to better and hopefully … more
today I want to describe interesting feature of Acumatica related to back ups of database. Imagine the following: you've restored database from back up at your dev environment. And let's say you have automation schedule that every hour you should send to each contact some emails. So, you've restored customization and would like to find the button that will block sending of all emails. At which screen it is? At none. It is interesting to know, that Acumatica already "pressed" at this button when you've restored db from back up. But for now you probably have another question. How to debug execute any schedule at all?
I propose following steps:
Delete all automation … more
today I want to make a short notice on how to change default time zone in Acumatica.
In my case such need appeard when it was needed to modify default time zone of Acumatica that I've restored from database backup. In order to do this you'll need to go to screen that is named Site preferences. Id of that screen is sm200505. more
today I want to describe one behaviour of Acumatica processing screen.
So, once upon a time I created processing screen. Purpose of that screen was simple: take data from some external source and insert it into Acumatica.
As that processing screen worked fine, it was taken a decision to create automation schedule step that will make that screen to be executed by Acumatica automatically. And then following issue arised: also that screen worked great in manual mode, it didn't work at all in Automation schedule mode at all.
After long investigation I found the following:
Automation screens are executed from the user acount admin
Also admin should have access to … more
Here in Ukraine there is a joke: nothing spoils health of Ukrainian more then richness and welfare of his neighbor.
Also I often hear statement that helping others can transform your life to better. I've spent some time on finding the ways to help others. But helping not via giving money. As one man once said give somebody fish for two times and for third time that person will demand fish from you. So I wanted to be a person that can give fishing rod to people instead of just giving them fish.
As result I've decided to teach some close friends of mine programming. Well, it is not a surprise because I'm quite skillful in that area and what else can I teach? And you know, it changed my … more
today I want to add few more notes about measuring of quality of learning, but today about tasks of classification.
So, one of the ways can be measuring number of wrong answers. For example with usage of the following formula:
Imagine that your classification set has three possible labels: a (10 elements ), b ( 15 elements ), c ( 20 elements ). And let's say that your model wrongly classified 2 out of a, 3 out of b and 4 out of c. In that case following formula is applicable:
Historically it happend that in classification tasks it is common to maximaze function, while in regression learning vice versa.
Another common measurement of quality of classification is … more
Today I want to describe some ideas about measure quality of learning.
First of all I want to point areas where you can apply those measurements. It can be in three areas:
For setting funtional during learning
For picking hyperparameters
For evaluation of ready made model
Another way can be combination. You can measure quality during learning with one measurement, but final model you can analyze with other measurement.
So, let's start with most common formula: mean squared error:
In words it reads the following: difference between prognozed value and desired value, squared, summed and finally averaged.
MSE has following featues:
Easily minimizable … more