Data Definition and 998 Threads

Homework Statement Calculate the acceleration of a ball rolling down an inclined plane and also note the error. I am going to solve it myself, so I will just give one sample. Distance covered by ball(error : +- 0.05 cm) .95m Time taken(error : +- 0.01 s) 1.19s Acceleration(with error)...

Hello, I am currently pursuing my degree in Mechanical Engineering, and was wondering what math courses were good to take after the basic math sequence has been completed (Calculus 1-3, Differential Eq & Linear Algebra.). I have an interest in mathematical modeling and data analysis, as...

$\triangle ABC,$ point D and point E are on segment BC given: (1)AC=15, BD=9, DE=11, EC=5 (2)$\angle BAD=\angle CAE$ Please find AB=?

I keep on reading that VLE data may be calculated from the Redlich-Kwong. In line with this, I have these questions: 1) How accurate is the VLE data generated with the Redlich-Kwong as compared to using the vapor pressures to calculate these VLE data? 2) Can you guys give me a link, or even...

Hi there, I have recently come across some data that is supposed to be random, but I don't think it is. I graphed it out and it sure doesn't look random. I also ran a couple of statistical tests such as the runs test, and they all say "not random." Visually, the data looks like a piece of...

Hi all. I'm trying to come up with a way to determine if the defectivity of a particular widget is 'different' to the usual defectivity of a widget. The difficulty comes from the fact that widgets are made in batches of 25. We'd like to investigate any widgets which have a higher (or lower)...

Hi Say I have a finite data set (frequency, absorption) and I would like to find the corresponding dispersion. For this I could use the Kramers-Kronig (KK) relation on the absorption data. What I would do is to make a qubic spline and then perform the KK-transformation. However, the absorption...

Does anyone have access to the current data about solar radiation reaching Earth's surface ? The most importaint is the UV range divided into UV-A, UV-B and UV-C. If not, then data from the past few years would also be fine. I need it for research but I cannot find anywhere such information.

I'm having trouble understanding what accelerometers really measure. In observing a simple gravity pendulum, the accelerometer recorded this data (jpeg image attached) which is acceleration in the vertical direction (supposedly). Now I've been told all sorts of things, like that the...

Hi all, I would like to know if there exists any method to represent multidimensional vectors on a 2D plot so using extracting any unique features of those vectors. Can eigen values be used for such purposes like dimensional reduction. If so how ? I would like to know more about these...

I'm trying to transform area values into raster data. I have areas, defined as circles (location of center + length of radius). Each area has a designated value between 0 and 2. I used Matlab's command area to plot the areas and also to designate the value that goes with each area. Now I want...

I'm working on monitoring and trending the performance of a memory controller. Without getting into the technical details, I'm trying to find a good way to visualize the data I've collected in a way that will be easy for me to update when I receive new data. There are about 450 individual...

Suppose the 2nd data can be read after the first data, but i need to restart the condition the only can read the 2nd data. By that, i have read the slave address again before the 2nd data has been read. So how should i solve it?

Hi all, i got a set of negative values ranging from -0.0001 to -0.3. How do i effectively make them easier to compare and plot a normal distribution graph. can i just do exponential on the values? Thank you for the help

I have a google spreadsheet with a display of numbers from a report that is ordered and the link below is the result of this data. It seems to me that there is a shape to the data that is showing. This shape seams to be constant over time having the same shape with a leading edge on the left...

Having some trouble with this. I think the answer to question 1 is 26% and question 2 is 2%. I'm not sure when to divide by 163 or 100?? practice test help: About 26% of orthopedic surgeries involves knee problems. The following table summarizes data collected from a sample of adults who have...

I have data from exhaust gas analyzer, and I have to find the calorific value or the heating value of that particular fuel using that data. Can anyone show me how to do that please. Or if there is any other way to find the calorific value of fuel. The data is in the attached pic

In my Fortran program, I want to read data from various files whose size I do not know in prior. The input files which I am trying to read may contain different number of entries. If I have same and known number of entries in all files (say 386), I can use something like...

I received an excellent question about significant figures when there is no actual numerical data given. In the figure below, we have a cube circumscribing a triangle and the task is to find the angle at M. N and M are midpoints of the cube's side. By using the Pythagorean theorem a few times...

Homework Statement Share market trading calculator. I have tried to write code to calculate the buy and sell with profit/loss on historical data using moving averages. I'm am not interested in leverage yet. bank = 10000 equity = 10000 sell = is current price of an instrument on the...

Hello everyone: I have some question using the FFT in MATLAB for data interpolating. I don't know what the relation between the normal Fourier series and the real, image number. For example, given a set of measurement data, I can use the curve fitting toolbox to fit a curve. The general...

Testing for chaos in data I have data for 3 variables ,each with respect to the discrete time values. How do I check for the existence of chaos for this discrete 3D system?(I don't have the analytic eqs.,just the data.) MY IDEAS ON CHECKING FOR CHAOS FROM DATA:(which of these are feasible...

Dear users I have some points with coordinate x and y forexample : x=[1 2 3 4] and y=[2 4 6 8] and then I want to fit these 4 pair of points with some function for example y=a*x+b (here I know that the answer is a=2 and b=0) what should I...

I have 2 measures that I am using to rank terms that I get them by prediction (using linear regression). They are the time to transmit X bytes and the time to compute the X bytes. I do the prediction if I execute in host A, B, and C. I add the 2 measures and rank the hosts. I think adding these...

I currently have hard-coded in my forecasting model, 6 weightings (totaling 100%) for 6 weather stations and wish to determine a methodology to produce these weighting or conversion factors % to form an artificial single weather station. This is part of forecasting the electricity load in my...

Hi I am not sure what method to use when analysing the difference in values between physical measured data and modeled data. This is to do with measuring the energy deposited at a point in water from a beam of photons. I have a set of physical measurements obtained whilst varying the...

Homework Statement I have a list of data in .csv format that looks like the following: 10 5 TRUE 10.1 5.1 TRUE 10.2 5.2 FALSE 10.3 5.3 FALSE 10.4 5.4 FALSE 10.5 5.5 TRUE 10.6 5.6 TRUE ... There are thousands of entries...

I have seen in books that when number of elements is small ~ 30-40 insertion sort is recommended. Why is that? The worst case of insertion sort is n2 whereas for quick-sort it is nlogn. nlogn beats n2 for all values of n isn't it? Then why?

Hello there, Let's say I have the following array: (what interests me in the array is the first column) 1 5 9 1 4 9 1 8 9 1 9 6 2 5 6 2 4 8 2 4 7 2 6 9 2 3 0 2 0 4 3 5 8 3 4 8 3 9 8 4 8 5 4 8 9 4 8 5 4 3 9 4 8 7 5 8 9 5 8 9 5 4 8 5 7 8 5 6 2 ... and so on...

I have a set of data that was recorded from an engine that we are testing. We've noticed lately that a particular pressure value will sometimes spike with no apparent explanation, as seen in the attached graph. The pressure in question is passively regulated by a pump, but it is also dependent...

Hi, I am trying to convert data to a particular range of 0-10. Actual Data may vary from - 50000 - 26214400. I have broken this down into 4 parts as follows - 50000 - 1048576 -----> 0 - 2.5 1048577 - 5242880 -----> 2.6 - 5 5242881 - 15728640 ----->5.1 - 7.5 15728641 - 26214400...

I would like to have P-V-T data for water in order to enter them in an Excel spreadsheet and design some exercises for the students to plot different kind of diagrams using the same data. I can generate the data using some suitable model, but I think that having real experimental data would be...

Hello, Im trying to model an RF attenuator for use in a control system. The control voltage is from 0-2.1V and I applied a step function signal from 0-2.1V and measured the output. I was able to model it as a first order system in the form Kdc / Xs + 1. The issue I'm having is...

Hi, I am not a mathematician, but I have noticed some recent papers on this seemingly new field, called Topological Data Analysis (see this relevant paper). I have had an overview of the applications and it seems that when you have data points that were sampled from some source (e.g. an...

Homework Statement If f(x/y) = f(x)/f(y) f(y)≠0 and f'(1)=2 find f(x). Homework Equations The Attempt at a Solution Diff both sides wrt x f'(x/y)*1/y=f'(x)/f(y) putting x=1 f'(1/y)*1/y=2/f(y)

I am starting my 3rd year in September and I've decided to start thinking about research topics early. I'm quite interested in piezoelectricity along with it's discovered and perhaps undiscovered applications. This is my first idea; I have watched a lot of nature programs and I have seen that...

How could one obtain a function y=f(x) that satisfies a number of data points (x_{i},y_{i}). That is how would it be possible to get a function if some points that are to lie on it have been given? I've seen some lectures on interpolation but all I've gotten is only the way to solve problems...

Hi, I've got a problem. There is over 9 milions points in my .txt. I have to find polynom for surface of this points with deviation smaller then 0.01 (x [-3:3], y[-3,3], z [-9,9]). I try many functions in Matlab, but no answer. Thank for help. B

I don't know whether this has much general interest. I am interested by communication horizons in cosmology, or causal horizons if you prefer. This paper claims to study several cases including how far apart two quasars would have to be to have been out of contact ever since the end of the...

Homework Statement An experiment was done to test the validity of the equation a = 2/3 g sin∅ for a rolling cylinder. A hockey puck was rolled down a wooden ramp at 5 different inclination angles, and the time it took to roll down the length of the board was recorded. ∅ was found using...

I've recently been assigned a project by one of my professors to animate a solar system style disc using real data computed from a simulation of his, and I'm wondering what the best angle of approach for this project would be. I have some experience in Cinema4D animating things, and I'm...

I have just about finished this program, I only need to calculate my velocity. I think that this velocity should be calculated by taking the value from the 4th column of my data set here:https://docs.google.com/file/d/0BzuDEPd26OcheVhiWlZ3STlZU0k/edit?usp=sharing which have called ivar_3 and...

I see there have been many postings about this topic in this forum. The formula for this relation is Luminosity = Mass^3.5 Taking logs of both sides we get log (lum) = 3.5 * log (mass) and using a little algebra we find that the exponent (3.5) should equal log (lum) ÷ log (mass) I have...

Hi all, I need to rearrange my data. I have an excel file with 12 columns and 2045 rows, which I transformed that into a .mat. I need to query my data rearranged as follows (cf. example matrix below): 1-sum all values of Col 3 if: a-they belong to a given value of Col 1 and to a...

So I have this set of statistical data, which is not completely relevant to what I want to model, and I would like to compensate for that somehow since I do not have the more precise data. I have about 500 observations of average wages in certain areas which are modeled as dependent on several...

Hello. I was just wandering if anyone could help. I've been doing a couple of statistics questions, and when they ask for some questions, I am not sure if I have an appropriate understanding of what the right answer should be. I would really like to understand this material, so what I want to...

For our physics lab we found the magnetic field produced by a magnet at different distances. When graphing the data, it was supposed to produce a linear graph when we plot the field strength against 1/r3. However, my graph doesn't become linear until 1/r5 (however, it does linearize quite nicely...

Greetings everyone, I need a good source that lists various properties of semiconductors such as band gap energy, effective mass of holes and electrons. Do you have a recommendation I looked at ISSP by Kittel and various other books but except band gap energy I could not find much...

Here is the question: Here is a link to the question: Help with Z Score Problem? - Yahoo! Answers I have posted a link there to this topic so the OP can find my response.

If we commonly draw a distribution of data, we should be careful to chose appropriate classes, for instance, 1-2, 4 2-3, 6 3-4, 11 etc. But, if we draw a cumulative distribution, classes are not necessary. For instance 1-2, 4 2-3, 10 3-4, 21 and still better: 1, 1 1.3, 2 1.4, 3 1.9, 4...