2701: Change in Slope - Revision history

PinkAmpersand: /* Explanation */ did someone seriously... whatever

2024-03-18T16:22:54Z

‎Explanation: did someone seriously... whatever

Xurkitree10: /* Transcript */

2023-04-20T06:37:45Z

‎Transcript

172.70.219.36: /* Explanation */

2022-12-13T08:44:14Z

‎Explanation

172.69.34.44: fixed residuals, added slope standard error comparison

2022-11-24T00:21:09Z

fixed residuals, added slope standard error comparison

162.158.166.231: /* Explanation */ not sure

2022-11-23T01:29:06Z

‎Explanation: not sure

172.71.154.38: /* Explanation */ Randall's suggested method

2022-11-23T01:27:49Z

‎Explanation: Randall's suggested method

172.69.33.11: /* Explanation */ inaccurate sentence

2022-11-22T18:22:19Z

‎Explanation: inaccurate sentence

172.69.22.27: /* Explanation */ not definite article

2022-11-22T16:26:04Z

‎Explanation: not definite article

172.71.158.217: revert self: the light grey

2022-11-22T16:24:23Z

revert self: the light grey

172.69.134.161: /* Transcript */ neither

2022-11-22T16:21:55Z

‎Transcript: neither

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 The comic compares two methods. Firstly, a novice method &mdash; by 'doing a bunch of statistics'- i.e, applying various statistical tools to analyze the data and figure out the quantitative change in slope. This results in two equations for the trendlines above and below a given value, a box plot, a histogram, and a line chart. It is unknown exactly what methods the novice used to figure out the change in slope in the data. Possibilities include calculating the [https://stackoverflow.com/a/45063636 derivatives] (which probably won't work well on noisy data such as shown), or [https://stackoverflow.com/a/71744293 gradients], or using a [https://stackoverflow.com/a/47522444 Savitzky-Golay filter or piecewise linear smoothing spline fits]. [[Randall]]'s light gray figures may be suggesting [https://colab.research.google.com/drive/1apKDIN5FE32mtGiQew5cE6wK6m6eM_Fr this method.]
-The other is the so-called 'expert' method, which involves [https://cdn.discordapp.com/attachments/525939879805190154/1044395695525875712/xkcd_sideways.png tilting the page the graph is printed on to view changes in slope] better. For small changes in an underlying trend, similar to that apparently shown in the comic, direct visual inspection cannot always identify or even reveal the effect. The comic shows, however, that by taking the page and rotating it in just the right way, the foreshortened perspective can make certain details much more apparent, allowing the 'expert' to see at a glance that there is a change in the slope. Ironically, tilting the comic to make the original roughly resemble the perspective of the 'tilted' version graph shown in the comic shows that the right-hand panel is slightly exaggerated for visual effect. The use of {{w|Perspective (graphical)|perspective}} to make information pop into the audience's view has been used by artists for {{w|The_Ambassadors_(Holbein)|centuries}}.
+The other is the so-called 'expert' method, which involves [https://web.archive.org/web/20221122041345/https://cdn.discordapp.com/attachments/525939879805190154/1044395695525875712/xkcd_sideways.png tilting the page the graph is printed on to view changes in slope] better. For small changes in an underlying trend, similar to that apparently shown in the comic, direct visual inspection cannot always identify or even reveal the effect. The comic shows, however, that by taking the page and rotating it in just the right way, the foreshortened perspective can make certain details much more apparent, allowing the 'expert' to see at a glance that there is a change in the slope. Ironically, tilting the comic to make the original roughly resemble the perspective of the 'tilted' version graph shown in the comic shows that the right-hand panel is slightly exaggerated for visual effect. The use of {{w|Perspective (graphical)|perspective}} to make information pop into the audience's view has been used by artists for {{w|The_Ambassadors_(Holbein)|centuries}}.
 However, applying such an approach to data plots can run into errors &mdash; the primary one being parallax error from the oblique viewing angle causing the observer to not necessarily identify or clearly find the point at which the slope changes. It also does not reveal any data about the quantitative value of the change in slope, merely proving the existence of one. Furthermore, noisy data might show an apparent slope change that is not representative of an actual change in the underlying data, so even more advanced [https://www.danielsoper.com/statcalc/calculator.aspx?id=103 statistics testing the hypothesis of whether an apparent slope change is real] may likely be a good idea.

← Older revision		Revision as of 06:37, 20 April 2023
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	==Transcript==		==Transcript==
−	~~{{incomplete transcript\|Do NOT delete this tag too soon.}}~~
−
	:How to detect a change in the slope of your data		:How to detect a change in the slope of your data

← Older revision		Revision as of 08:44, 13 December 2022
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	==Explanation==		==Explanation==
−	~~{{incomplete\|Created by a SIDEWAYS STATISTIC. Do NOT delete this tag too soon.}}~~
−
	The comic is a tip for detecting changes in slopes over a {{w\|scatter plot}} of data. This is a common requirement in exploratory statistics for comparing trends in a series — finding the cutoff where the slope changes may reveal valuable information about the data.		The comic is a tip for detecting changes in slopes over a {{w\|scatter plot}} of data. This is a common requirement in exploratory statistics for comparing trends in a series — finding the cutoff where the slope changes may reveal valuable information about the data.

@@ Line 14: / Line 14: @@
 The comic is a tip for detecting changes in slopes over a {{w|scatter plot}} of data. This is a common requirement in exploratory statistics for comparing trends in a series &mdash; finding the cutoff where the slope changes may reveal valuable information about the data.
-The comic compares two methods. Firstly, a novice method &mdash; by 'doing a bunch of statistics'- i.e, applying various statistical tools to analyze the data and figure out the quantitative change in slope. This results in two equations for the trendlines above and below a given value, a box plot, a histogram, and a line chart. It is unknown exactly what methods the novice used to figure out the change in slope in the data. Possibilities include calculating the [https://stackoverflow.com/a/45063636 derivatives] (which probably won't work well on noisy data such as shown), or [https://stackoverflow.com/a/71744293 gradients], or using a [https://stackoverflow.com/a/47522444 Savitzky-Golay filter or piecewise linear smoothing spline fits]. [[Randall]]'s light gray figures may be suggesting [https://colab.research.google.com/drive/1Ru90DAxHO9zzXrx-_4P28UJ_8MaHT0RL this method.]
+The comic compares two methods. Firstly, a novice method &mdash; by 'doing a bunch of statistics'- i.e, applying various statistical tools to analyze the data and figure out the quantitative change in slope. This results in two equations for the trendlines above and below a given value, a box plot, a histogram, and a line chart. It is unknown exactly what methods the novice used to figure out the change in slope in the data. Possibilities include calculating the [https://stackoverflow.com/a/45063636 derivatives] (which probably won't work well on noisy data such as shown), or [https://stackoverflow.com/a/71744293 gradients], or using a [https://stackoverflow.com/a/47522444 Savitzky-Golay filter or piecewise linear smoothing spline fits]. [[Randall]]'s light gray figures may be suggesting [https://colab.research.google.com/drive/1apKDIN5FE32mtGiQew5cE6wK6m6eM_Fr this method.]
 The other is the so-called 'expert' method, which involves [https://cdn.discordapp.com/attachments/525939879805190154/1044395695525875712/xkcd_sideways.png tilting the page the graph is printed on to view changes in slope] better. For small changes in an underlying trend, similar to that apparently shown in the comic, direct visual inspection cannot always identify or even reveal the effect. The comic shows, however, that by taking the page and rotating it in just the right way, the foreshortened perspective can make certain details much more apparent, allowing the 'expert' to see at a glance that there is a change in the slope. Ironically, tilting the comic to make the original roughly resemble the perspective of the 'tilted' version graph shown in the comic shows that the right-hand panel is slightly exaggerated for visual effect. The use of {{w|Perspective (graphical)|perspective}} to make information pop into the audience's view has been used by artists for {{w|The_Ambassadors_(Holbein)|centuries}}.

@@ Line 14: / Line 14: @@
 The comic is a tip for detecting changes in slopes over a {{w|scatter plot}} of data. This is a common requirement in exploratory statistics for comparing trends in a series &mdash; finding the cutoff where the slope changes may reveal valuable information about the data.
-The comic compares two methods. Firstly, a novice method &mdash; by 'doing a bunch of statistics'- i.e, applying various statistical tools to analyze the data and figure out the quantitative change in slope. This results in two equations for the trendlines above and below a given value, a box plot, a histogram, and a line chart. It is unknown exactly what methods the novice used to figure out the change in slope in the data. Possibilities include calculating the [https://stackoverflow.com/a/45063636 derivatives] (which probably won't work well on noisy data such as shown), or [https://stackoverflow.com/a/71744293 gradients], or using a [https://stackoverflow.com/a/47522444 Savitzky-Golay filter or piecewise linear smoothing spline fits]. [[Randall]]'s light gray figures seem to be suggesting [https://colab.research.google.com/drive/1Ru90DAxHO9zzXrx-_4P28UJ_8MaHT0RL this method.]
+The comic compares two methods. Firstly, a novice method &mdash; by 'doing a bunch of statistics'- i.e, applying various statistical tools to analyze the data and figure out the quantitative change in slope. This results in two equations for the trendlines above and below a given value, a box plot, a histogram, and a line chart. It is unknown exactly what methods the novice used to figure out the change in slope in the data. Possibilities include calculating the [https://stackoverflow.com/a/45063636 derivatives] (which probably won't work well on noisy data such as shown), or [https://stackoverflow.com/a/71744293 gradients], or using a [https://stackoverflow.com/a/47522444 Savitzky-Golay filter or piecewise linear smoothing spline fits]. [[Randall]]'s light gray figures may be suggesting [https://colab.research.google.com/drive/1Ru90DAxHO9zzXrx-_4P28UJ_8MaHT0RL this method.]
 The other is the so-called 'expert' method, which involves [https://cdn.discordapp.com/attachments/525939879805190154/1044395695525875712/xkcd_sideways.png tilting the page the graph is printed on to view changes in slope] better. For small changes in an underlying trend, similar to that apparently shown in the comic, direct visual inspection cannot always identify or even reveal the effect. The comic shows, however, that by taking the page and rotating it in just the right way, the foreshortened perspective can make certain details much more apparent, allowing the 'expert' to see at a glance that there is a change in the slope. Ironically, tilting the comic to make the original roughly resemble the perspective of the 'tilted' version graph shown in the comic shows that the right-hand panel is slightly exaggerated for visual effect. The use of {{w|Perspective (graphical)|perspective}} to make information pop into the audience's view has been used by artists for {{w|The_Ambassadors_(Holbein)|centuries}}.

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 [[Category:Charts]]
 [[Category:Scatter plots]]
 [[Category:Statistics]]