Publications by R on Thomas Roh
Shiny in Production: App and Database Syncing
When using shiny in production, often you will want to have some sort of database interactions for storing and accessing data. The DBI package provides an easy way to do the database interactions with a variety of SQL database flavors. In this example, I’m going to use a SQLite in memory database for reproducibility. In practice, yo...
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Shiny in Production: App and Database Syncing
When using shiny in production, often you will want to have some sort of database interactions for storing and accessing data. The DBI package provides an easy way to do the database interactions with a variety of SQL database flavors. In this example, I’m going to use a SQLite in memory database for reproducibility. In practice, you will just ...
2223 sym R (2543 sym/9 pcs)
Introduction to leaflegend
leaflegend is a package to extend the customization of legends for the leaflet package in R. The addLegend function provides some great out of the box legends based on the internal palette functions, but styling of the legend components has to be done with external css code as in this example. leaflegend allows the user to add images ...
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Introduction to leaflegend
leaflegend is a package to extend the customization of legends for the leaflet package in R. The addLegend function provides some great out of the box legends based on the internal palette functions, but styling of the legend components has to be done with external css code as in this example. leaflegend allows the user to add images to legends, ...
2605 sym R (4166 sym/6 pcs) 10 img
Map Symbols and Size Legends for leaflet
The leaflet package in R has built-in functionality for creating color encoded geometries and annotating with color legends. Support is lacking in the area of providing the ability to encode data with sizes or symbology except for the case of circle markers. Size and symbology are an important part of data visualization on a map. Usin...
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Shiny in Production: Database Transactions
An important aspect of maintaining databases with an application interface is to ensure atomicity. When performing multiple writes on a database, any failures that occur during the operations should not violate any logical rules. The most common analogy is a financial transaction. If person A withdraws X dollars from their account and deposits in...
4199 sym R (5538 sym/4 pcs) 10 img
Fast SQL Server Imports with R
Writing large datasets to SQL Server can be very slow using the DBI package with an odbc connection. The issue with writing data is that individual INSERT statements are generated for each row of data. I’ve also had issues with remote connections that can make large writes to SQL Server take a very long time. SQL Server Management Studio does p...
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Awesome Marker Legends in Leaflet
The awesome-markers plugin that ships with the leaflet package provides a great way to add iconography to points on a map. Three different icon libraries are supported, you have the ability to change to a few different options for the marker colors: , and can specify the icon color (it’s a font!) with any specification that is supported in HTM...
1794 sym R (2155 sym/1 pcs) 4 img