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# Category Archives: Excel

## US Farmland % By State

I am preparing to drive out to Idaho to experience totality during the August 21, 2017 eclipse. I am choosing to view the eclipse from Idaho because my granddaughter (and her parents) live in western Montana, and I can stop there for visit when I return to Minnesota. This will be a long drive through large states (Minnesota, North Dakota, Montana) that have a significant percentage of farm land. While planning my journey, I became curious as to the percentage of farmland in each of the fifty states. In this post, I compute the farm land percentage by taking the farm acreage in each state and dividing by the state's land area (water area removed). Continue reading

Posted in Excel
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## An Example of Cleaning Untidy Data with Tidyr

I recently decided to take some classes in data analysis at Datacamp, an online training site. My first classes were in dplyr and tidyr – two excellent R-based tools for manipulating files that not amenable to analysis because of inconsistencies and structure: tidyr provides many tools for cleaning up messy data, dplyr provides many tools for restructuring data. After completing the two classes, I decided that I needed to firm up my knowledge of these tools by applying them to a concrete example. Continue reading

Posted in Excel, History Through Spreadsheets
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## Quick Look at Large US Dams

I was on the phone this morning with a coworker who lives in California, about 150 miles south of the Oroville dam (Figure 1). This dam has recently been in the news because of concerns that spillway erosion could cause a dam failure. At one point, nearly 200K people were evacuated from the potential flood zone. Continue reading

Posted in Excel, History of Science and Technology
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## Fact Checking: US Murder Rate Over Time

I recently saw a politician claim that the US murder rate is the "highest it's been in 47 years." This is an easy fact to check and provided me another Power Query example to provide for my staff. Continue reading

Posted in Excel, Fact Checking
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## History Through Spreadsheets: Executive Orders

During my recent seminar on Excel's Power Query feature, I showed my team how to grab data executive order data from the web and generate a simple plot (Figure 1). After generating the plot, I asked the audience what we could learn from this graph. I was expecting to hear that the early 1900s – the time between Teddy Roosevelt and Franklin Roosevelt – was a time of massive use of executive orders. Continue reading

## Calorie Per Acre Improvements in Staple Crops Over Time

My family has strong agricultural roots – mainly in dairy and potato farming – and our holiday conversations frequently turn to discussions of crop yields (bushels per acre or lbs per acre). As I listened to the discussion between my brothers on this year's crop yields, I realized that the yield numbers they were quoting were much higher today than we saw as children. This made me curious, and I decide to go out to the US Department of Agriculture's National Agricultural Statistics Service crop database and download CSV files on the yield of some key staple crops for processing by Power Query (i.e. recently renamed Get and Transform). I will be using this file to train my staff on defining Power Query functions. No macros were used in this analysis. Continue reading

## Using Excel's Solver and VBA For Repetitive Table Calculation

I will be providing some employee training on Excel in January, and I need an example of how to automate the use of Excel's Solver add-in – a powerful optimization tool that few engineers use effectively. When I give a training seminar, I make a serious effort to show how I use Excel on real problems. While I generally use Mathcad for most optimization applications, Mathcad does not support integer programming – an optimization method where some or all variables are restricted to be integers. Here is where Solver shines – it supports integer programming. Continue reading

Posted in Construction, Excel
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## Excel Data Table with More Than Two Input Variables

I am a big fan of Excel data tables, but I often struggle because they are designed to work with one or two input variables and a single output function. Many of calculations that I do have more than two input variables that I need to vary. These calculations also often have multiple output values. This post discusses how to create a data table with more than 3 input variables and more than one output variable. Continue reading

Posted in Excel
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## Using Excel's Icon Sets for Testing Equality -- Ugh

I use Excel everyday, but that does not mean that I have used every feature. Yesterday, I was asked to prepare an analysis for our marketing group of the maximum possible distances that over which a customer can be served using various types of fiber optic communication systems – we call this parameter "reach". During this analysis, I saw what I thought was an ideal opportunity to use Excel's icon sets for the first time (Figure 1). Continue reading

Posted in Excel
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## Optical SFP Power Estimation Using Curve Fitting

I was asked today how to use Excel to estimate the power usage of two optical components at case temperatures for which we had no data. I initially solved the problem in Mathcad by fitting an equation of the form $latex c_0 \cdot e^{c_1 \cdot T_{Case}}+e_2 to the data and computing the corresponding power. Continue reading

Posted in Excel, General Mathematics
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