Publications by The USGS OWI blog
The Hydro Network-Linked Data Index
Introduction The Hydro Network-Linked Data Index (NLDI) is a system that can index data to NHDPlus V2 catchments and offers a search service to discover indexed information. Data linked to the NLDI includes active NWIS stream gages, water quality portal sites, and outlets of HUC12 watersheds. The NLDI is a core product of the Open Water Data Init...
11277 sym R (16082 sym/8 pcs) 6 img
Groundwater levels across US affected by Mexico earthquake
What happened? A magnitude 8.1 earthquake was measured in the Pacific region offshore Chiapas, Mexico at 04:49:21 UTC on September 8th 2017. Working in the Water Mission Area for the USGS, our Data Science Team was already hard at work polishing up water visualizations for the devastating Hurricane Harvey, as well as creating a new visualization ...
5939 sym R (4010 sym/8 pcs) 5 img 1 tbl
Daily Streamflow Trend Analysis
Introduction This document describes how to produce a set of graphics and perform the associated statistical tests that describe trends in daily streamflow at a single streamgage. The trends depicted cover the full range of quantiles of the streamflow distribution, from the lowest discharge of the year, through the median discharge, up through th...
22462 sym R (18669 sym/14 pcs) 13 img
Maps with inlmisc
Introduction This document gives a brief introduction to making static and dynamic maps using inlmisc, an R package developed by researchers at the United States Geological Survey (USGS) Idaho National Laboratory (INL) Project Office. Included with inlmisc is a collection of functions for creating high-level graphics, such as graphs, maps, and cr...
5388 sym R (7437 sym/16 pcs) 3 img
Beyond Basic R – Introduction and Best Practices
We queried more than 60 people who have taken the USGS Introduction to R class over the last two years to understand what other skills and techniques are desired, but not covered in the course. Though many people have asked for an intermediate level class, we believe that many of the skills could be best taught through existing online materials. ...
7466 sym
Beyond Basic R – Data Munging
What we couldn’t cover In the data cleaning portion of our Intro to R class, we cover a variety of common data manipulation tasks. Most of these were achieved using the package dplyr, including removing or retaining certain columns (select), filtering out rows by column condition (filter), creating new columns (mutate), renaming columns (rename...
8652 sym R (7838 sym/13 pcs) 4 img
Beyond Basic R – Plotting with ggplot2 and Multiple Plots in One Figure
R can create almost any plot imaginable and as with most things in R if you don’t know where to start, try Google. The Introduction to R curriculum summarizes some of the most used plots, but cannot begin to expose people to the breadth of plot options that exist.There are existing resources that are great references for plotting in R: In base ...
5699 sym R (3294 sym/5 pcs) 5 img
Exploring ggplot2 boxplots – Defining limits and adjusting style
Boxplots are often used to show data distributions, and ggplot2 is often used to visualize data. A question that comes up is what exactly do the box plots represent? The ggplot2 box plots follow standard Tukey representations, and there are many references of this online and in standard statistical text books. The base R function to calculate the...
7089 sym R (17790 sym/15 pcs) 7 img 4 tbl
Beyond Basic R – Mapping
Introduction There are many different R packages for dealing with spatial data. The main distinctions between them involve the types of data they work with — raster or vector — and the sophistication of the analyses they can do. Raster data can be thought of as pixels, similar to an image, while vector data consists of points, lines, or polyg...
5462 sym R (7255 sym/7 pcs) 6 img
Beyond Basic R – Version Control with Git
Depending on how new you are to software development and/or R programming, you may have heard people mention version control, Git, or GitHub. Version control refers to the idea of tracking changes to files through time and various contributors. Git is an example of a version control tool, and GitHub is a popular web interface for Git. That’s it...
4141 sym