Error In Slope Of A Line
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Springs Charge of an Electron Video Analysis Torque Rolling Objects Mechanical Energy Human Performance Old labs Extra Stuff Slope uncertainty Reports How to find the uncertainty in the slope This is an issue that I have not really addressed much. However, it is important enough that I talk about it. In many labs, you will collect data, make a graph, standard error of slope of regression line find the slope of a function that fits that data and use it for something. Well, what if
Error In Slope Linear Regression
need to find the uncertainty in the slope? How do you do that? There are a couple of ways you can do this, neither are absolutely correct. However, error in slope of linear fit if you write a formal lab report and you find the slope you MUST find the uncertainty in it. Here is some sample data. Suppose I measure the diameter and the circumference of several roundish objects. Here is my data. So, I want to plot
Percent Error Slope
this and find a functional relationship between these two. With error bars, this is what it should look like: Now, I want to fit a linear function to this data. That should be ok, but what about the uncertainty? Method 1 - use uncertainty of data points I could get the ratio of C/d by just looking at each data point. This is not as good as the slope because the slope essentially uses all the data points at once. In this method, I am going to find the slope as normal. error in slope calculator In Excel, you could fit a trendline. Or, you could draw a best fit line. Either way, I would get something like this (I did this in Logger Pro): This gives a slope of 3.28 (compare to pi = 3.14). I could get a better slope if I required the fitting function to go through the origin (0,0), but I am not going to do that. In essence, the slope is: But, what if I just use one set of data points? Then I could use propagation of error as usual. This would give Where the delta - slope represents the uncertainty in the slope. For this method, just pick the data pair with the largest uncertainty (to be safe) - although hopefully, it won’t matter much. For this case, I will pick d= 0.06+/-0.002 m and C = 0.183 +/- 0.004 m. This would give an uncertainty in the slope of 0.2. I would write: (there are no units - they canceled) Method 2 The next method is better but a little tricky. Basically, if you draw a best fit line you could “wiggle” the line and still have it fit. This would give a minimum and a maximum slope. If you do the trendline in Excel, I am not sure how you would do this. If you do it by hand on graph paper, it would be easy. Here, I am going to manually fit two lines in Logger Pro. Here is the max slope that ‘looks’ like it fits. This gives a min slope of 3.0 and a max of 3.2 for an uncertainty of +/- 0.1. Announcements| Labs|
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Error In Slope Excel
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How To Find Standard Error Of Slope
machen Schließen Dieses Video ist nicht verfügbar. WiedergabelisteWarteschlangeWiedergabelisteWarteschlange Alle entfernenBeenden Wird geladen... Wiedergabeliste Warteschlange standard error of slope formula __count__/__total__ Uncertainty in Slope of Trendline Michael Sheehan AbonnierenAbonniertAbo beenden88 Wird geladen... Wird geladen... Wird verarbeitet... Hinzufügen Möchtest du dieses Video später noch https://www2.southeastern.edu/Academics/Faculty/rallain/plab193/page1/page35/page36/page36.html einmal ansehen? Wenn du bei YouTube angemeldet bist, kannst du dieses Video zu einer Playlist hinzufügen. Anmelden Teilen Mehr Melden Möchtest du dieses Video melden? Melde dich an, um unangemessene Inhalte zu melden. Anmelden Transkript Statistik 4.486 Aufrufe 3 Dieses Video gefällt dir? Melde dich bei YouTube https://www.youtube.com/watch?v=_zkXtScFwcM an, damit dein Feedback gezählt wird. Anmelden 4 2 Dieses Video gefällt dir nicht? Melde dich bei YouTube an, damit dein Feedback gezählt wird. Anmelden 3 Wird geladen... Wird geladen... Transkript Das interaktive Transkript konnte nicht geladen werden. Wird geladen... Wird geladen... Die Bewertungsfunktion ist nach Ausleihen des Videos verfügbar. Diese Funktion ist zurzeit nicht verfügbar. Bitte versuche es später erneut. Veröffentlicht am 03.09.2012Uncertainty of Slope Kategorie Film & Animation Lizenz Standard-YouTube-Lizenz Mehr anzeigen Weniger anzeigen Wird geladen... Autoplay Wenn Autoplay aktiviert ist, wird die Wiedergabe automatisch mit einem der aktuellen Videovorschläge fortgesetzt. Nächstes Video How to calculate the error in a slope using excel - Dauer: 9:11 Maxamus 14.769 Aufrufe 9:11 IB Physics: Uncertainty in Slope using Excel's LINEST - Dauer: 7:04 Chris Doner 6.170 Aufrufe 7:04 Using LINEST in Excel - Dauer: 4:30 Jared Spencer 166.300 Aufru
The http://web.alfredstate.edu/quagliato/linest/linest.htm Linest() function in Excel gives the error (or uncertainty) for data in the lab. It calculates the statistics for a line https://www.mathworks.com/matlabcentral/answers/53884-determine-the-the-slope-and-its-uncertainty by using the "least squares" method to calculate a straight line that best fits your data, and returns an array that error in describes the line. Because this function returns an array of values, it must be entered as an array formula. An array should be entered in the four boxes. The array represents the following: error in slope Error in the Slope To determine the +/- error in the slope and the y-intercept, an array must be created. Go back to the original spreadsheet and highlight 4 empty boxes as shown below. Click the mouse in the formula box and enter the LINEST function. =LINEST(B2:B12,A2:A12,true,true) The B2:B12 interval represent the known y values and the A:2:A12 interval represent the x values. The LINEST function will evaluate the errors in the slope and y-intercept for a data set. The const and stats should be labeled true and true as shown below. IMPORTANT: To enter an array, hold down the Ctrl and Shift keys at the same time and then press Enter.
Support Answers MathWorks Search MathWorks.com MathWorks Answers Support MATLAB Answers™ MATLAB Central Community Home MATLAB Answers File Exchange Cody Blogs Newsreader Link Exchange ThingSpeak Anniversary Home Ask Answer Browse More Contributors Recent Activity Flagged Content Flagged as Spam Help MATLAB Central Community Home MATLAB Answers File Exchange Cody Blogs Newsreader Link Exchange ThingSpeak Anniversary Home Ask Answer Browse More Contributors Recent Activity Flagged Content Flagged as Spam Help Trial software Lizan (view profile) 53 questions 2 answers 0 accepted answers Reputation: 1 Vote0 Determine the the slope and its uncertainty? Asked by Lizan Lizan (view profile) 53 questions 2 answers 0 accepted answers Reputation: 1 on 16 Nov 2012 Accepted Answer by Jos (10584) Jos (10584) (view profile) 4 questions 850 answers 259 accepted answers Reputation: 1,864 534 views (last 30 days) 534 views (last 30 days) Hi,I am trying to linearly fit a set of data points, find the slope and then compute the uncertainty of the slope, +, - uncertainty. How can I do this in MATLAB?I have tried to look into regression and regress but are getting very confused.Additional questions:What is the outputs of Regress? Does it gives the slope of the linear fit? And the 95% confidence intervals? I noticed that b not the same as the polyfit?Likewise, the polyfit does not give the same slope as regression. And Regression gives me matrix of result.. shouldn't slope just be one value. The inputs are just vectors of x,y data.Thanks 0 Comments Show all comments Tags regression Products MATLAB Related Content 2 Answers Jos (10584) (view profile) 4 questions 850 answers 259 accepted answers Reputation: 1,864 Vote0 Link Direct link to this answer: https://www.mathworks.com/matlabcentral/answers/53884#answer_65537 Answer by Jos (10584) Jos (10584) (view profile) 4 questions 850 answers 259 accepted answers Reputation: 1,864 on 16 Nov 2012 Accepted answer Do you also want to fit an offset? Polyfit does that for you, but you have to tell regress exp