KNN Classifier does not show accuracy against trained data

[engageaffli]

Dear ml5 community,

I'm submitting a new issue. Please see the details below.

→ Step 1: Describe the issue 📝

Did you find a bug? Want to suggest an idea for feature?

I am trying to add a single class instead of multiple classes to identify the distance between the trained data to the test data. But the confidence score is always 1 for any image since there is only 1 class added to it.
I would like to know how to get the accuracy percentage for KNN similar to custom object detection model.
Is there any evaluate function that I can use to get the accuracy when training a single class.

→ Step 2: Screenshots or Relevant Documentation 🖼

Here's some helpful screenshots and/or documentation of the new feature

→ Step 3: Share an example of the issue 🦄

Here's some example code or a demonstration of my feature in this issue, separate GitHub repo, or in the https://editor.p5js.org or codepen/jsfiddle/Glitch/etc...

Other relevant information, if applicable

→ Describe your setup 🦄

Here's some helpful information about my setup...

• Web browser & version:
• Operating System:
• ml5 version you're using:
• Any additional notes