Skip to main content

Plot csv data using D3.js

I tried my first D3.js data visualization using csv data source


My 'graph' would plot circles, where the x position of the circle would represent the value of the second column (file size) in my csv. The larger files would be plotted to the right.

I posted my example d3csv.html at https://github.com/binodpanta/webvisualizer

I should be able to do some more interesting things with this, such as realtime monitor files.

Enjoy!

Comments

Popular posts from this blog

Unit testing code that uses environment variables and system properties with fakes

I did not exactly learn this today, but I am sharing it as I have found it extremely useful when unit testing code that depends on environment or system property settings. While I am using Java as an example, the general concepts apply any where. Problem : You have a piece of code you are unit testing that uses settings from env variables or system properties passed to the VM (System.getProperty), but you don't want the tests to be affected by the 'real' environment or system properties in the VM. So, your unit tests should not get different results or fail when the real environment changes. Solution : There are several. But the most straightforward is to use a mocking library to mock out the environment or fake it out, whatever your prefer. You can create a fake using a library like EasyMock, PowerMock etc. This I won't discuss in this post, since there are numerous articles for that. Or you can write a simple class that acts as a proxy, using the proxy pattern...

Using custom conditional logic to enable/disable Spring components

If you have a Spring component and you don't want it to load, you can use Spring's predefined conditionals as much as possible. For example, @Component   @ConditionalOnNotWebApplication   public class SchedulerEntryPoint implements ApplicationRunner { ...  } This will not load your component when running in non web application mode. Such as you may want to start the application but without any of the web framework using SpringApplicationBuilder. But sometimes you want to use custom conditions. It's pretty easy to do so, just use something like this @Component @Conditional (SchedulerCheck. class ) public class SchedulerEntryPoint implements ApplicationRunner { public static class SchedulerCheck implements Condition { @Override public boolean matches(ConditionContext conditionContext, AnnotatedTypeMetadata annotatedTypeMetadata) { return System. getProperty ( "scheduler" ) != ...

Sending Form data to a backend REST API using Axios

This need is incredibly common and useful, and hopefully will save you a lot of time when doing server side calls from your UI application (or even non UI clients like NodeJS applications) Example here is to send a POST request to an endoint /api/item/new (which will create a new item in the database). We will just assume tbhe backend is already setup (it's not relevant to this article). All we need to know is that we can do a POST /api/item/new and send it form data with two pieces of info     name, filter So, if you have a node.js application (I was using Vue-cli generated project, but it does not matter), install 'axios' (a most popular tool to make server calls these days) npm i axios --save OR yarn add axios (my preferred method) Now, in your service JS file (which is generally when I keep all my api calls) do something like this createNew ( name , filter ) { let formData = new FormData (); formData . append ( "name" , ...