Simple File Manipulation in a Console Application with C++

The goal of this tutorial is to show you how to make a C++ console application that will read data from a file called "input.txt" that's formatted like this (with each new entry on its own line):

1234567
1234567
1234567

and output it to a file called "output.txt" that is formatted like this (standard CSV (Comma Separated Values) format, except with 25 columns per row maximum):

1234567,1234567,1234567,...(25 times)
1234567,1234567,1234567,...(25 times)
1234567,1234567,1234567,...(18 times)

Averaging Multidimensional Data for D3

Building from the example in my previous tutorial, I am only going to slightly modify a few aspects of the graph. My goal for this tutorial is to show how to code the graph differently such that the 3 pieces of data per row are averaged together into 1 piece of data per row.

Using Multi-Column Data with D3 Part 2

Okay, so after reading my previous tutorial we are now capable of loading in a CSV file with multi-column data and completely reconstructing it.

That's great! but... what about being able to categorize, filter, (somewhat) transition, and color the representation of that data? That's what this tutorial is all about! :)

Using Multi-Column Data with D3 Part 1

In my previous tutorial, I showed how to import data from a CSV file or a text file. However, oftentimes the type of data that you need to use has multiple columns, like so:

Column 1 Title, Column 2 Title, Column 3 Title
1, 2, 3
4, 5, 6

rather than being in a single column format, like this:

1
2
3
4
5
6

One common reason for having multi-column data is if all of the data can be split into categories and you need to visually show which category each piece of data is in, through colors, spacing, positioning, highlighting, font size, or etc.

In this tutorial, I'm just going to show you how to fully reconstruct the data by accessing it in memory, as it's not entirely the simplest thing for a beginner to do. Once we're able to access individual pieces of data, we'll be able to create multi-column/multi-category graphs, filter out certain categories of data, color them, etc.

Using CSV (and Text) Files with D3

This tutorial is in response to a request by someone who wanted to know how to use data from CSV (Comma Separated Values) files with D3. Interestingly enough, you will also see how the data can be stored into and read from a simple text file (instead) along the way.

The CSV file format is commonly used in spreadsheets, and it's pretty well known to programmers as one of the easiest formats to read and write data with. Why? Take a look at what a CSV file's contents could be:

2345, 345, sdfgsd, 3453,
wgdg, 34, fsg, dgd, 34534.634,

sfsfggsdfgsdfgsdfh, 4, "hello",
-2

If you look past the stupidity of the bogus "data" I used in that example, you'll see that it's fairly simplistic! Every value is separated by a comma - hence, Comma Separated Values (CSV).

Before I show you how to use CSV, you should know that I made an "Introduction to D3" tutorial earlier. I highly recommend that you read it first.