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Archive for April, 2018

Earth As Art Astronomy Day Program

Saturday, April 21st, 2018

Planet Earth As Art: The View From Space Program
Planet Earth As Art: The View From Space Program

Today (Saturday, April 21) I will be giving my Planet Earth As Art: The View From Space presentation as a part of the Astronomy Day event being held at Harper College in Palatine IL. I find the timing of this talk most appropriate since tomorrow is Earth Day.

In this presentation, I give a brief introduction to remote sensing and spend some time talking about the workflow and techniques I use to take the source image data, mostly coming from the Landsat 8 mission, and process it so as to create visually attractive images.

The presentation contains some images of cities for scale reference but focuses on natural features like deserts, islands, volcanoes, glaciers, sediment flows, and river deltas. Some of the images I use in my presentation can be seen in my Planet Earth Satellite Imagery Collection on Redbubble.

Some images from Planet Earth As Art
A few images from the Planet Earth As Art presentation (rotated 90 degrees here)

For details about the Astronomy Day activities at Harper College, please visit the Northwest Suburban Astronomers Astronomy Day page.


Jim Plaxco’s Art Portfolio on Redbubble


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Best Day and Time for Art Sales on Redbubble

Monday, April 16th, 2018

Redbubble Sales by Day of Week Graph
Illustration 1: Redbubble Sales by Day of Week Graph

Do a google search and you will find an abundance of results for answers to questions like "what is the best time to post on social media?" (For example, see my post Best Times to Post to Facebook, Linkedin, and Twitter) or "what is the best time to send email blasts?" or "what is the best time to sell on eBay?". But what about "what is the best time to sell on Redbubble?" Running this question past Google I got lots of results for "how to sell on Redbubble" but nothing regarding the "when" aspect.

Redbubble obviously knows the answer to the question of when most sales occur but doesn’t share that information. In doing my income taxes this year, I was going over my merchandise sales on Redbubble and decided that I wanted to know when most of my sales on Redbubble were being made. So instead of continuing to work on my taxes as I should have, I decided to take a break and do some simple data analysis.

There were two questions I wanted to answer. First, what is the best day of the week for my Redbubble sales and second how are my sales distributed across the week by day of week and time of day.

The starting point for any analysis is getting the data needed to perform the analysis. When artists are logged in to their Redbubble account, on the Account Settings page (labeled as Account Details in the dropdown menu), there is an Artist Tools section with one of the menu items in that section being Sales History.

Redbubble Sales History CSV
Redbubble Sales History CSV

Within Sales History there is a feature for downloading a CSV file of your sales history. The data in this file is very useful if you want to identify which of your artworks generate the most sales or the most income. It will also allow you to see which products are the most frequently sold. For this analysis, we are only interested in date and time of day when sales were made. While the file does have a field for the order date, there is no time of day information.

Fortunately I’m a pack rat when it comes to data. As a seller on Redbubble, generally when a sale is made I receive a "You’ve Made A Sale" email. I say generally because I’ve had multiple instances of receiving a "Manufacturing Invoice" email for which there was no companion "You’ve Made A Sale" email. What is useful about the "You’ve Made A Sale" email is that the email not only has the transaction date but it also has a time stamp. Assuming that Redbubble consistently generates these emails within 15 minutes of the actual transaction time, this data can be used as a proxy for the transaction time of day information.

Best Day of the Week for Redbubble Sales

The first analysis I did was to simply tally by day of week when sales were occurring and to then calculate what percentage of total sales happened on that day. The graph of that data is shown in Illustration 1: Redbubble Sales by Day of Week Graph at the top of this post while the following table ranks the days of the week in order of their sales volume.

Day of
Percent of
Sunday 18%
Tuesday 18%
Monday 15%
Friday 15%
Thursday 12%
Wednesday 12%
Saturday 09%

The data for my sales indicates that the three day period of Sunday through Tuesday are when most of my sales are made and account for 51 percent of all sales. Note that if sales were evenly spread across all days, then any three days of sales would account for just under 43 percent of all sales. Saturday is clearly a trough day for me on Redbubble with only half the sales volume of the peak day.

Redbubble Sales Heatmap: Time of Day by Day of Week

Taking the analysis one step further, I broke out each day into the hour of the day in order to see at what time during the day sales were being made. Again I must point out that I do not know how closely the timestamp on the "You’ve Made A Sale" email correlates with the time the customer actually completed the transaction. For this analysis I assume a high degree of correlation.

Rather than using colors for this heatmap, I’ve opted to use a simple grayscale value since I’m simply looking at a single simple variable — sales frequency. The results are shown in Illustration 2: Redbubble Day of Week and Time of Day Sales Heatmap. A value of black means that no sales were made during that hour. A value of white represents the peak hour of the week. The rest of the grayscale values, from darkest to lightest, represent the range of least to most sales per hour.

Redbubble Day of Week and Time of Day Sales Heatmap
Illustration 2: Redbubble Day of Week and Time of Day Sales Heatmap

The heatmap shows that the single best hour for sales during the week is during 10:00am to 11:00am on Friday, which is curious since Friday is not a peak day of the week. Sunday from 11:00am to 4:00pm appears to be the best block of time for sales during the week.

Is This Redbubble Sales Data Actionable?

So now I know when I’m making sales and my curiosity has been satisfied. But is there any way that I can use this data to my benefit? Maybe. For example, if there is a good correlation between the times that sales are made and the level of activity in the Redbubble Groups, posting artwork to the relevant groups during these peak sales hours may result in a sales boost.

Another possibility is dependent on the answer to the question "How much of a search results boost does Redbubble give to newly added artwork?" It’s a given that the makers of search engines don’t want to tip their hand as to how their search ranking algorithm works because they do not want people to "game the system" — which makes perfect sense. If we assume that a peak in sales corresponds with a peak in customer visits to Redbubble and if we also assume that Redbubble does give some sort of search results boost to new artwork, then an artist may marginally help their sales over time by adding new art to their account at the front end of a period of time for which the sales volume is above average.

Concluding Thought

There are a lot of unknowns associated with this analysis. A key unknown is just how well my sales data aligns with Redbubble’s site-wide sales data. For those familiar with astronomy, there is the concept of the homogeneous universe. If that concept (that the universe is the same everywhere) applies to my sales data for Redbubble, then there will be a high degree of correlation between my results and the results that any other artist doing a similar analysis would get — in which case this analysis would be useful to anyone selling their art and/or photography on Redbubble.

For any artist or photographer engaged in selling on Redbubble, I hope you have found this information useful and that you will consider following me on Redbubble.

Visit Jim Plaxco’s Artist Portfolio on Redbubble

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Ambient Recursion Algorithmic Art

Tuesday, April 10th, 2018

Ambient Recursion Algorithmic Art
Ambient Recursion Algorithmic Art cropped version.
Click the image to see the uncropped version.
The original artwork is 30 by 30 inches printed at 300ppi.

What could be the first in a series of algorithmic artworks, Ambient Recursion was created using a programming technique known as recursion. Note that the image above has been cropped to fit the screen. To see the complete artwork, click on the cropped image above. A new window will open revealing the complete artwork. Note that a full size excerpt from the center of the artwork is displayed at the bottom of this post. Once you’ve viewed the uncropped image, it will be clear that while the artwork is strongly symmetrical, it is not perfectly symmetrical. I find that by avoiding perfect symmetry, the image becomes more interesting and aesthetically pleasing.

The programming language I used for this work was the Processing programming language. The most challenging part of writing this Processing program was in getting the recursion to perform as I wanted it to – especially with respect to screen boundary conditions.

Because I used a random factor to determine which sub-functions would be called, which in turn influenced the depth of recursion, I found that much of the drawing was being done off-screen – or so I guessed when viewing the program’s output. To get a handle on just where the drawing was happening, I replaced the drawing commands with print commands that dumped out the x,y coordinates and other supporting parameters for every shape being drawn.

This problem solving tactic proved to be most useful as it led me to reevaluate the entire drawing process. If I could dump the coordinates and associated parameters of every shape to a print file, why not write them to a Java arrayList and then draw using the data stored in the list. While the principal benefit of this approach was in insuring that every rectangle would appear within the canvas, it also provided me with the opportunity and ability to manipulate the relationships between the shapes. This was a true case of serendipity.

The second most challenging aspect was in coming up with a title. Given the nature of the image and the fact that I was listening to a collection of ambient music by Brian Eno while developing and writing the program used to create this artwork, the title Ambient Recursion was a natural choice.

While I have not yet added Ambient Recursion to my gallery of artworks here on Artsnova, I have made it available on Redbubble.

Ambient Recursion Algorithmic Art on Redbubble

Ambient Recursion Samsung Galaxy Smartphone Case


Ambient Recursion full size excerpt Case
A full size excerpt from the center of the artwork.


What is Recursion?

Using the definition from Geeks for Geeks, recursion is:

The process in which a function calls itself directly or indirectly is called recursion and the corresponding function is called as recursive function. Using recursive algorithm, certain problems can be solved quite easily. Examples of such problems are Towers of Hanoi (TOH), Inorder/Preorder/Postorder Tree Traversals, DFS of Graph, etc.

For more about recursion, see the Wikipedia definition for Recursion (computer science)

And remember…

To iterate is human, to recurse divine.
L. Peter Deutsch


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