Given Points On Curve, Solve For Equation
Feb 25, 2009Is it possible in excel to find the equation for a curve?
I have 6 known x,y data points on a curve. I need to find the equation for the curve.
Is it possible in excel to find the equation for a curve?
I have 6 known x,y data points on a curve. I need to find the equation for the curve.
Can excel solve an equation for x with two variables.
Example: 102=125000(X-910)/50000.
I need excel to solve for X
The variables are 102 and 125000
I am trying to calculate the equation of a curve which best fits some data. On the x-axis is date and y-axis the readings. The curve is quadratic, so on the chart I am fitting a 2nd order polyomial and displaying the equation. To prove that the equation the trendline gives me is reasonable, I am applying the equation on the x parameter to get the y parameter estimate and looking to see the error between predicted and actual - see attached.
The equation and the output from it are clearly rubbish, even though on the graph the trendline is a reasonable fit - see attached. Has anyone any ideas why? I think it has something to do with using a date on the x-axis but no idea why. Is there a way to correct for this? I also tried using the following I to calculate the coefficients which came up with a reasonable forecast (although linest should only be used for linear data): =LINEST(C3:C15,B3:B15^{1,2,3})
Is there a way I can get Excel to sum/count in an IF equation if the condition falls between 2 points?
For instance:
I want to count the amount of days between two dates.. I am currently looking at something like:
=If(cell>[date1]&cell<[date2],sum(cell yada yada....)
Using <> wont work in this instance.
I have a data set (Set#1) that consists of a positional rank (1-240) and a dollar value ($46-$1) for each positional rank. It's not a straight line set.
DataSet.JPG
What I need to do is take that curve and apply it to another data set (Set#2) (1-240) and assign a dollar value ($46-$1) to each positional rank.
A "corner cutting" way of doing it would be an Index/Match to simply carry over the dollar value from (for example) #45 from my Set#1 to #45 in my Set#2. This could work reasonably well with data sets of the same size, but mine aren't always the same size, so I need to apply the curve itself. I
Is there a way of amending the following line of code so that it selects multiple data points in a data series in a chart (e.g points 14,15,16)?
ActiveChart.SeriesCollection(2).Points(14).Select
I have spreadsheet that tracks the the rain total for several days. I would like to be able to break it down to the days of weeks that has rain and how much without manually imputing the data.
Days | #of times | total amount
Mon
Tue
Wed
Thu
Fri
Sat
Sun
to allocate funds to various organisations with a number of constraints (see spreadsheet attached I work in Excel 2007 but saved the file in 2003):
1. No negative growth can be allowed (Column M which is difference between columns Q and B) and I therefore added Column N to bring the growth in Column R to 0% for those which had a growth of less than 6%.
2. Minimum growth however allowed should be 6%
3. Maximum growth allowed should be 50% (not all need to have 50% growth)
4. The balance of the allocations to organisations with growth more than 50% should be used to "equalize" allocations proportionately between the other organisations with growth lower than 50%
I am solving a mass balance for my wastewater class and need help using excel for find my unknowns. I have solved down to this EQN; 35,000=2367(SRT)/(1+.088*SRT) + 31.2(SRT)^2/(1+.088*SRT) + 88.8(SRT)/(1+.06*SRT) + 449*SRT + 224.6*SRT
SRT is my unknown.
I am trying to solve a set of simultaneous equations by using SolverOk function in VBA.
I dont want to use the 'SetCell' option so, I wrote the following
SolverOk MaxMinVal:=1, ByChange:= Range("V34:V36")
SolverAdd CellRef:=Range("AK4:AK6"), Relation:=2, FormulaText:="0"
SolverSolve
but I get an internal memory error. However, if I use the solver dialog box directly from excel and not through a macro and keep the 'Set Target Cell' as empty, I get the right solution.
How to solve table with filter which needs to be copy to other tab.
Example: One tab has table with filter. Issue is with another tab which needs to be copy but issue is that another tab will further investigate with additional columns. Can be solved this issue as first tab will filter and change all rows order and another tab should read content with added columns.
I need the formulas to solve for the ARC length AB.
(How) can Excel solve this?
I will have to solve many variations of the 1 inch length and/or vary other measures.
Known's
Arc radius 1.5
Slope angle 31 degrees
Slope intercept to center of Arc Diameter 1
Circle B radius .75
Circle B is tangent to Slope
Solving the Segment length AB would be a bonus.
Given a list of numbers and a list of 'allowable' operators, come up with a specific total. ("The numbers game" on countdown on BBC2.... ooooh Carol Voderman)
For example, given the numbers 1, 3, 4 and 5 with valid operators +, -, /, * come up with a solution equal to 15. All numbers must be used once only. Use operators as often as required. The specific example above was given to me and I personally think its not solvable (might be a practical joke). But I am wondering is it possible to prove this through assertions or develop an algorithm to solve such puzzles. I can get 14 and 16, but not 15....
I am attempting to create a formula that is including numeric values in multiple cells but I want to exclude cells that have an "N/A" value. I am calculating the blended average price using the volume and price from multiple cells but some cells don't have volume or price but an "N/A" instead. The blended average price should be $68 but how do I calculate that including all the cells...even the cells including the "N/A"
Attachment example included.
Need to solve the formula in the file. Is it possible to solve this in just one move? in that case.
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I am looking for a function [or method] to calculate a polynomial curve fit. I can do it on a graph with the existing graph and chart tools, but I need to calculate it myself. Does such software exist somewhere in my Excel 2007 package, or can anyone recommend a freeware program? I am hesitant to download an unknown, un-recommended add-in.
i am getting some data via RS 232 port and plotting it straight to excel, which comes out to be in forms of waves you can say sine waves, now i need to calculate area under the curve, say like if i highlight some area it will automatically calculate the area, or if i select two points on the curve it will calculate the area. please help me out i am really stuck at this part.
View 9 Replies View RelatedI'd like to apply a curve to a column of student exam grades and have the curved grades displayed in the adjacent column. Here is how I'd like to curve:
I like to make a linear function out of two coordinate pairs.
First Pair (x1,y1) = (Highest Exam Grade, 99) = (H,99)
Second Pair (x2,y2) = (Class Exam Average, Desired Exam Average) =(C,D)
Slope = (99-D)/(H-C) = m
Linear Function = Y-y = m(X-x) = Y-99=m(X-H)
Each student grade would = "Y" i.e. Y=m(X-H)+99
How I can find a max in an xy chart curve fit?
View 9 Replies View RelatedDoes anyone know of a statistical formula that would create a normal growth curve?
For example. Let's assume that I want to forcast growth from January through December. I know that in January I will have 100 units. In December, I will have 1,000 units. Is there a formula to predict the the units in Feb-Nov (using a normal growth curve)?
I am working on Project Planning, I need to create the Progress curve for our Project based on Weight Factor every month.
I need to create the Plan and actual curve based on the dates defined in particular activities. Once the activity progress is calculated every month based on cut off date then it will sum product with corresponding WF to get the progress achieved every month. Presently I am calculating the values every month and pasting the values in Chart data every month. I had created the S Curve and attached here.
Now my objective is to automatically calculate the values for the entire cut off date at one time (From Project Start to End). i.e I don't want to do any manual work in the Chart. I will update only the actual Dates in the file, then the curves need to get automatically updated.
1) I don't want to calculate the progress for individual activities, I would like to calculate the overall progress directly.
2) When I change the Cut off date, then the previous values needs to become static.
I'm trying to find a formula that would spread out a value amongst multiple cells along a bell curve. Say I have $x,xxx. I want to spread that amount out in a certain proportion, regardless of how many cells I'm spreading it throughout.
Say I have a $10,000 project. I want to be able to spread it out like a bell curve in the cells I choose. For instance, if it was a five month project it would be distributed as
January - $1,000
February - $2,500
March - $3,000
April - $2,500
May - $1,000
If I added another month it would change to
January - $833.33
February - $1,666.66
March - $2,500.00
April - $2,500.00
May - $1,666.66
June - $833.33
I already thought of manually adding percentages to each cell, but the formula needs to be dynamic.
Can we draw tangent to a curve in excel graphs..? If yes if i could have some demo....** this.. I am working on finding rate ** change at an instantaneous point and average rate ** change ie: secant line
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A sample is attached : Excel forum-Lab data.xlsx
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