I'm not quite familiar with QGIS, but now I have used too much time trying to find a solution of my probably trivial question.
So I have data for Danish administrative areas. So far I have calculated centroids and added y and x coordinates for them. However, I have not been able to convert them to decimal degrees when exporting as CSV. In the "Save Vector Layer as..." I tried changing the CRS to EPSG:4326 which was what I read would do it. But when I export the CSV, the format is not as such (between -180 and 180 for the y coordinate for example).
I would appreciate some help.
Sincerely,
Emil Blicher
Related
I have two CSV files, each file contains list of 3D points include X, Y, and Z that represents a point in 3D space. The number of points in each file is not equal.
I write a program that reads points from CSV files and renders by OpenGL.
How can I measure the "distance / thickness (the space)" between two curved surfaces?
Are there any concepts / formulas about distance between two curved surfaces in 3D space?
Any keywords, theory, examples, illustrations, etc will help me very much.
Thanks and best regards,
Hi I have attached my graph and my data below:
My experiment is on Simple Harmonic Oscillators in an RLC circuit. I need to work out the quality factor. Where I need delta w which is the width of the resonance curve at imax/sqrt(2). With the Y axis being my current and Imax being 0.4229 so 0.4229/sqrt(2) = 0.299. So I need to read the frequencies (x values) at the points 0.299 on the y axis in order to work out the width. I was wondering how I can do this on excel. Obviously if this was on paper I could just draw straight lines but I'm on excel and unsure and hoping someone could help. Thanks
looking for a bit of assistance
I want a scatter graph with the X axix showing performance of an investment fund comparative to the Y axis which will have a volatility value.
Thus far the scatter graph takes the data and separates the two values out, I want the scatter plot to have incorporated both figures.
I have included an image showing, if someone could point out where I am going wrong?
Thanks in advance
ScatterGraph
When inserting your chart, make sure you choose the second option:
I'm not great with Math at all and so-so with Excel. I have a requirement to calculate a series of values to apply as an offset for a price schedule. I know what I basically want to achieve with the offsets and how I want them to change across span of values but I don't know how I can plot these values or something close to it in Excel. For an idea of the curve I'm roughly trying to create you can plot these values:
0
20
30
35
38
39
39.5
40
40.5
40.75
41
41.125
41.25
Or if you don't want to use excel you can take a look at this chart image:
Now it was easy to quickly create that by entering some values and tweaking them to get a shape I roughly want, but I need 1000 data points! In other words, instead of the 13 point I provided above I would need 1000. This would be crazy to try and do manually.
I can think of two possible options:
Create the range of values with fewer points, then somehow
extrapolate that data set into more points. Maybe extrapolate isn't
correct but essentially convert 10 points of data into 1000
Interactively draw a curve and then have it plotted to values within
a defined min/max range
I've tried googling for help but I'm just coming up with tons and tons of "how to plot your data" sites - I need to work from the OTHER direction ;)
Thanks for any help or tips.
Like you said, you could draw a curve and plot those points, then put them into some equation solver to get an equation that could describe the curve you're looking for.
But just from looking at your curve above, you might be able to use an equation of the following form.
y = A - (B / x)
To make a curve similar to yours above, you might try...
y = 40 - (5 / x))
You can use a site like https://functionplotter.com/ to plot the function and play with the values of A and B until you have curve that you are satisfied with.
Is this kind of thing you are looking for?
spline interpolation in exel
XlXtrFun.xll
basically you already got 13 y's and 13 implict x's (1 to 13). You provide bunch of "x" values of small increment, like 0.01, 0.02, 0.03, ...,12.999 13.000, to this tool. then this tool will calculate y value for each of the ones. You will plot these as "x y scatter plot"
A simple and very accurate way is to plot the curve as an x-y scatter plot, and then fit a polynomial via Insert Trendline.
In this case a 4th order polynomial provides close to a perfect fit (R2 of .9973)
Y = -0.0139x4 + 0.4819x3 - 6.0607x2 + 33.026x - 26.718
You can also solve this without charts using LINEST, see Walkenbach's guide here. But charts provide the easiest reference
Most simple thing to do on paper, but somehow near impossible to work out in Excel.
I need to interpolate off a standard curve in Excel.
I have a standard curve and need to find an unknown concentration of a known absorbance.
Just like this;
http://class.fst.ohio-state.edu/fst601/Lectures/spectt/Image161.gif
My lecturer would not give us any more hints than to either use the, linear regression equation (which i think i worked out but couldn't get it to calculate the concentration) or use the point finding/picking option (no idea what this could mean)
If anyone could help me out with this I would really appreciate it, and so would my whole class!
In excel, you can do it two ways:
Method 1: Use a standard interpolation/extrapolation formula. (Bingle)
Method 2: Plot any existing data points that you have as an x-y(scatter) plot. Right-click on the data line in the chart and choose 'Add trendline'. Excel will calculate a best-fit line for your data (using linear regression) and display the line over the top of your existing data. If you right-click on this trendline, you can adjust its settings and display properties of it, including the equation used to draw it. Once you have that equation, you can plug in any value of x and get the corresponding value of y.