calculate the standard deviation

Similar Questions

• How to calculate the standard deviation of a certain number of points?

  Hi, I have a request that I acquire signals of strength and Pu, then on a table.

  I need to calculate the standard deviation and the mean each a number of points, 1000 for example.

  I have problems with this, if you can help me I would be grateful.

  Thank you

  Douglas

  If you need something like this?

  

• need a script to custom calculation to calculate the standard deviation

  need a calculation script customized to calculate the standard deviation of 8 rows, it is a form .pdf variable data entry points will be users using this model as a form.

  I can get the average of simple calculation, but struggling with the script for the standard deviation. Any help would be appreciated.

  Header 1	Header 2	Header 3	Header 4	Header 5	Heading 6	Heading 7	8 header	Header 9	Header 11
  sample1Row1	sample2Row1	sample3Row1	sample4Row1	sample5Row1	sample6Row1	sample7Row1	sample8Row1	Average	stdDeviation

  If the formula is not:

  StdDev = sqrt (sum (sampleXRow1 - average) ^ 2 / (n-1))

  But:

  StdDev = sqrt (sum ((sampleXRow1-average) ^ 2) / (n-1))

  If the code should be something like this:

  var avg = Number(this.getField("AverageRow1").valueAsString);
  var sum = 0;
  var n = 0;
  for (var i=1; i<=8; i++) {
      var v = this.getField("sample"+i+"Row1").valueAsString;
      if (v!="") {
          sum+=Math.pow((Number(v)-avg),2);
          n++;
      }
  }
  if (n==0 || n==1) event.value = "";
  else event.value = Math.sqrt(sum / (n-1));
  

• Aggregator customized to calculate the standard deviation

  Hello
  This is probably already available or easy to implement, but I find it difficult to find samples for writing a custom aggregation and ParallelAwareAggregator.
  
  I'm figuring the difference type of a variable in my item being cached in a real-time system. I want to aggregate the result sum [(X-X') ^ 2] where I spend X' (average) of the client. Can someone help me with an example?
  
  Thank you
  Sairam

  Hi Sairam,

  in fact, you probably have better use the single-pass approach to calculate the standard deviation, as the average of the values may change before you calculate the number of entries and the average gap.

  You can use the following formula to calculate the standard deviation in one pass: sqrt (N * sum (sqr (Xi)) - sqr (sum (Xi))) / N, where the sqr function is the square of a value, the square root function is the square root of the value, N is the number of entries and Xi is the value to calculate the gap type from the entry of the i - th.

  You can do something like this:

  public static class StdDeviation implements ParallelAwareAggregator {
  
    public static class PartialResult implements Serializable {
  
        private long numberOfElements;
        private BigDecimal sum;
        private BigDecimal sumSquare;
  
        public PartialResult(long numberOfElements, BigDecimal sum, BigDecimal sumSquare) {
            this.numberOfElements = numberOfElements;
            this.sum = sum;
            this.sumSquare = sumSquare;
        }
    }
  
    public static class ParallelPart extends StdDeviation implements EntryAggregator {
  
       private ParallelPart(ValueExtractor extractor) {
          super(extractor);
       }
    }
  
    private ValueExtractor extractor;
  
    private transient boolean notParallel;
  
    public StdDeviation(ValueExtractor extractor) {
      this.extractor = extractor;
      this.notParallel = true;
    }
  
    public Object aggregate(Set entries) {
       ValueExtractor extractor = this.extractor;
       BigDecimal sum = 0;
       BigDecimal sumSquare = 0;
       long num = 0;
       for (InvocableMap.Entry entry : (Set) partialResults) {
          sum = sum.add(partialResult.sum);
          sumSquare = sumSquare.add(partialResult.sumSquare);
          num += partialResult.numberOfElements;
       }
  
       return calculateStdDeviation(num, sum, sumSquare);
    }
  
    public EntryAggregator getParallelAggregator() {
  
       // you could return this, instead of ParallelPart
       //
       // return this;
  
       return new ParallelPart(extractor);
    }
  
    private static Number calculateStdDeviation(long num, BigDecimal sum, BigDecimal sumSquare) {
       BigDecimal partRes = sumSquare.multiply(new BigDecimal(num)).subtract(sum.multiply(sum));
  
       // you can replace the square rooting of a double value with a proper implementation of square root for BigDecimals,
       // which I omitted for the sake of brevity, and then you can do BigDecimal division (make sure you provide a MathContext)
       return Math.sqrt(partRes.doubleValue())/num;
    }
  
    public static Number execute(NamedCache cache, ValueExtractor extractor) {
       return (Number) cache.aggregateAll(AlwaysFilter.INSTANCE, new StdDeviation(extractor));
    }
  }
  

  There is actually no reason for the class ParallelPart to exist. I put it here to illustrate that there can be a different aggregator instance to the ParallelAware aggregator optimized to run on the side of the storage, but you could just "this" return of the getParallelAggregator() method, it wouldn't make a difference for this implementation of the aggregator.

  You can replace the rooting square a double value with a good implementation of the square root of BigDecimals, which I omitted for brevity, and then you can make division BigDecimal (make sure that you provide a MathContext)

  I also omitted the ExternalizableLite and PortableObject implementations (and necessary parameterless constructors) for brevity of the ParallelPart and PartialResult classes.

  In addition, you may need some mojo if you want to use a PofExtractor instead of a regular Value Extractor to avoid the deserialization of the cached value.

  You can perform the aggregation with the execute method, passing the cache altogether on the Extractor which extracts the value as a BigDecimal value cached.

  Best regards

  Robert

  Published by: robvarga on March 12, 2010 11:36

  Published by: robvarga on March 12, 2010 11:43

• How to get the standard deviation of parameter curve nonlinear

  Hello, I tried to understand (as here in the forum) how to obtain the standard deviation for the parameters of a nonlinear curve (Lev - Mar). The most interesting I found was on the Matrix of Covariance. Here the most reliable information came from DSPGuy (Message 8). But in the example VI it first takes the square root of the diagonal elements of the covariance matrix, and then multiplies these values with the RMSE (using the 'appropriateness' VI) to get the standard deviation of the parameters. In the thread, out of time, that it has been said that one has first to multiply the diagonal elements with the MSE directly from the Lev-Mar-VI.

  And another question is always there for me. That came in the previous mentioned thread:

  What is the DOF?

  a: N_MeasPoints - N_FittingParameters

  b: N_MeasPoints - (N_FittitngParameters - 1).

  If I understand the help for the 'appropriateness' VI a: must also be right, as the DSPGuy States. But I always thought that b: should suit like Peter Vijn2 said in the previously mentioned thread.

  Best thanks in advance

  Wolfgang

  Adding to the Christian post.

  1. If our documentation is incorrect, so let's fix it.

  2. I checked our source code for the CLN in the goodness of Fit.vi implements the DOF as our States to help.  They agree.  As the Christian States, if a different definition is appropriate for a given application, then you have the option to provide this value for the DOF.  I would add that the results that we return to the example related to the original message of Wolfgang tally with the results that the NIST certifies this problem to 8 decimal places.

  3 the form Christian mentioned, old implementation of Lev - Mar had an entry called "gap".  We have mapped to a weight using weight = (1/STD dev.) ^ 2 Christian to map the weight gap is therefore exactly what we used before.

  -Jim

• Hibernating virtual XP mode a message displays the standard deviation of CPU

  My Windows 7 has an XP mode VM hibernating works fine until I update my computer with a newer processor now when I try running VM pop a message: ' Windows XP Mode'could not be restored because of the type of host processor mismatch or lack of in the system hardware-assisted virtualization support "I think what I need is to reset this virtual machine to redo the setting, can someone help me? Thanks in advance.

  Hello

  Thank you for contacting Microsoft Community.
  You must enable hardware virtualization assisted from the BIOS. For the procedure, see the manual of your PC.
  If this fails to solve the problem, you must reset the virtual machine.
  Usually, when all important hardware, CPU, RAM or motherboard is upgraded, Hibernate will not resume. So, before you do the upgrade of the above mentioned components, please shut down the PC (even if it is virtual) and then proceed to the improvement.

• error of standard deviation

  I have a data set where all values are the same, but labivew is not a standard 0 deviation when I perform this calculation in a loop. Please see the .vi attatched. (Maybe I'm on something obvious).

  

  Computers cannot exactly represent numbers in floating point. The standard deviation, you have found is a small number, it is actually zero. You could easily test to see if it less than some others, very small number and set it to zero if you want.

• standard deviation for the slope of the linear fit

  I need away from the slope of the linear fit.

  Please confirm me if what I do is correct.

  I use the 'delta slope '' of the linear intervals did change the trust level of 0.95 to 0.68.

  But again, I'm not sure I can identify the slope delta as the deviation of the slope.

  Thank you

  Hello

  I did some research more.

  As I understand it, slope delta (or radius of trust) can also be referred to as margin for error.

  You may need to do more research on your own in this regard, but it seems that the two are different types of analysis. Standard deviation is a measure of the variability of a set of data, while the slope delta (or margin of error) refers to the amount of random sampling error. If you can get a direct link between the two, I'm not sure, however the first link below indicates that this is possible.

  http://stattrek.com/AP-statistics-4/margin-of-error.aspx?tutorial=AP

  http://en.Wikipedia.org/wiki/Standard_deviation

  http://en.Wikipedia.org/wiki/Confidence_interval

  http://en.Wikipedia.org/wiki/Margin_of_error

  I hope this gives some more.

  Regarding the algorithm we use in the interval linear form VI, I think that the following document would be a good start.  There is a section called "confidence interval and interval of forecasting."    It describes the algorithm we use.

  I hope this helps!

  Bye,.

  Licia

• Adobe Acrobat Standard DC - calculate, the value is the "sum" of

  The "text field properties / calculate / value is the 'sum' of the following fields / pinch / field selection"window does not provide any options to select. "  I formatted all the fields in the source & field sum as 'number' and out spaces in domain names.  My version of Acrobat Standard DC excludes a Sum function?  Thank you, all!

  It displayed fine. It looks good, so I don't know why there is no fields displayed when you click the button to 'Pick '. I always use the JavaScript option, but you can try the option of simplified field notation to work around the problem. You need to enter something like:

  Field1, Field2, field3 and field4

  Where are the names of the fields that you want to calculate the total, so change to match your domain names.

• FPGA - windowed moving average, variance, standard deviation, kurtosis and asymmetry

  Hello!

  I'm processing in FPGA and I want to calculate the MOVING WINDOW average, variance, standard deviation, kurtosis, asymmetry online for the last N (N is the size of windows) elements. The frequency is about 100 kHz and N about 10000 (100 ms of signal).

  I found something like EMA (moving average exponential)...

  Have someone solved something like that? Any ideas how to fix?

  That looks like a problem. What type of window you need? The moving average exponential isn't an option? There are online algorithms described in Wikipedia, but they can suffer from problems of numerical accuracy when it is implemented in a fixed point (depending on the nature of the data). They would be interesting watch in, however.

  Other than that, here are some options that I can think of:

  • More large FPGA
  • Be part of the treatment on the RT controller - have - you looked into that?
  • Return to your needs and push some of the numbers. Do you really need 100 ms in all cases, etc.?
  • Depending on the nature of the data, simple compression techniques may be an option
  • An precision analysis to determine the data type minimum, that you really need. For example, getting to 25 bits, would have a huge impact on your cost of multiplier.
  • Consider the mathematics of floating (using Xilinx IP cores) point to online methods. Your flow is relatively low, so you could share it resources between all channels. Manage States of different channels is complicated but is doable.

  The BRAM will be used for FIFO buffers, but is also available for general use to implement the fifo and memories. Some IP use BRAM under the hood, keep an eye on the compilation summaries to monitor how much still you have.

• Adjustment of curve: standard deviation given

  Hello

  Using LabView and estimators. Following situation:

  I have 15points including their standard deviation. I also have set up my estimators with my individual Gaussian fitting. Basically the editing seems good.

  But how can I say labview to take care of my already calculated gap.

  I always compare it with my editing (same equation Gauss) OriginPro. If I only take my data X and Y, I get the same results.

  But when I indicate also my SD (originally), which means that X, Y and +-Y, I get a more realistic result.

  And that's what I would do with LabView so but there is no possibility to take my + y into account, isn't?

  (And no, the original for LabView screws offer me this as well.) To the I don't see )

  Someone at - it a trick?

  Thanks in advance

  That's what the matrix of weights

  Just use the reciprocal of variances

  Understand the math is useful, read using the fitting vi is the first step

  Oh, the fitting screw of LabVIEW have a weighting of entry: 0

• calculate the difference of unique column values

  I tried the info and the website to learn how to perform a "calculation difference" function on a single column (channel) of data.  For example if my data channel is a period of time to say the following: 100, 101, 99, 102, 100, 99...  I would like to calculate 100-101 101 - 99 then then 99-102 and so on for all the values.  How can I do this?

  Hi ranger,

  Looks like you're looking for the standard function "Calculate the disparity" ANALYSIS > basic math.

  Hope this helps,
  Ralf

• How to calculate the space needed to move a member to another pool?

  Dear,

  We move - Member3 - member to a pool of maintenance for the upgrade of the firmware.

  My question is how can we calculate the space needed to move a member to another pool?

  I have attached some pictures of SANHQ for the pool/ability/member of the group.

  

  PS To consider space group not the pool area, because we have a fourth demo maintenance pool member and we it will move to the default pool for the process of upgrade only.

  Kind regards

  Turki

  Try this:

  GrpName > show Member - poolinfo
  Name State Version discs capacity FreeSpace connections pool
  ---------- ------- ---------- ----- ---------- ---------- ----------- -------
  Virt2-Mem2 V6.0.6 (R3 16 6.8 TB TB 5.53 208 ActiveP online
  51932)                                             ool
  Virt2-Mem3 V6.0.6 (R3 16 6.8 TB TB 5.95 Alterna 36 online
  51932)                                             tePoo
  l
  Virt2-Mem1 V6.0.6 online (R3 16 23.08(a) TB TB 21.44 209 ActiveP
  51932)                                             ool

  Re: cancel the mapping.  Some points to remember.  Cancel the MAPPING does not work on the replicated volumes, it's either sync replication or point-in-time standard.   Also according to the file system, it will not immediately reclaim the unused space on existing volumes.   Some file systems like VMware VMFS does not cancel the map on the fly, but offer a CLI utility to create large balloon files then delete and send him UNMAP commands simultaneously.

  The basic rule is that you must have enough space to move the member selected out of the pool.   If this isn't the case, then the operation will not be allowed.  You may end up having to add the new Member to the pool until you can move a table.

  Note: If you do not already done, then the site of Equallogic, with FW downloads is a document that describes how to set the value of disktimeout for several OS.   This allows the host (or the guest virtual machines) to cross the short breakdown during a firmware update or a failover of controllers due to a failure of the CM.

  Kind regards

• How to calculate the 99th percentile of a stream of number...

  Environment:
  
  Oracle 11.2.0.3 EE on Solaris 10.5
  
  I have a stream of numbers (for example 1000), I need to calculate the 99th percentile of the distribution of this stream in such a way that when a new ' number is introduced, I can tell if the new number is above the 99th percentile of the distribution of my workflow.
  
  I don't have a good idea of the nature of the distribution if it's important.
  
  I am NOT, I repeat NOT a statistician! :-)
  
  I read the docs on the different functions available, ntile, percent_rank, percentile_cont, percentile_disc, etc. I also read a lot of articles referenced via Google.
  
  The examples are not exactly what I'm trying and I was unable to get the result I need by trial and error (mostly!).
  
  All suggestions are welcome!
  
  If you need additional information, I will try to provide what I know.
  
  -gary

  Hi, Gary.

  garywicke wrote:
  Hi Frank

  Well to try to facilitate the description of periods, I managed to confuse the issue a little more.

  Sorry about that.

  I need to use days not months. The script will be executed every day and watch period of ago 210 days to 31 days following there from 30 days at present.

  With respect to the expected result, I need somehow calculate what turnover represents the 99th percentile (or 90th everything that works in the example) and store that in my table of this customer.

  Then after a CREATE TABLE statement for this table and you want that it contains, given the data published in the sales table, after it is filled.

  Another process on the whole will consider the last average of 30 days and determine if this average exceeds sales 99th percentile figure and initiate an action (alert email, etc.) if it is.

  My problem is that I don't know how to calculate this 99th percentile number.

  After the sample data, I'm guessing it should be close to the number of SD 3, but after reading your comments, maybe that's not correct.

  That's my guess. Sometimes deviations corresponding to percentiles, sometimes they did not. People choose one or the other, depending on what amounts to their data, and what they want to show on these data. Your client has apparently chosen percentile. Unfortunately, we do not seem to know something about the problem.
  Before you can solve this problem for your customer, you must understand what the problem is. Talk to your client and know exactly what is wanted here.

  Here is one possible approach.

  WITH     got_month_avg     AS
  (
       SELECT       custno
       ,       AVG (amount)     AS month_avg
       FROM       sales
       WHERE       tran_dt     >  SYSDATE - 30
       AND       tran_dt     <= SYSDATE
       GROUP BY  custno
  )
  ,     got_threshold_amount     AS
  (
       SELECT DISTINCT
            custno
       ,     PERCENTILE_CONT (.4)          -- or .99
                WITHIN GROUP (ORDER BY  amount)
                          OVER ( PARTITION BY  custno )          AS threshold_amount
       FROM    sales
       WHERE     tran_dt     >  SYSDATE - 210
       AND     tran_dt <= SYSDATE -  30
  )
  SELECT       a.custno
  ,       a.month_avg
  ,       t.threshold_amount
  FROM       got_month_avg          a
  JOIN       got_threshold_amount  t  ON  t.custno  = a.custno
  --WHERE       a.month_avg     >= threshold_amount
  ORDER BY  custno
  ;
  

  Output:

  `   CUSTNO  MONTH_AVG THRESHOLD_AMOUNT
  ---------- ---------- ----------------
           5      126.5           4812.6
          26 4602.44444           3102.2
  

  I set the WHERE clause comment, just so that we could see the results of each custno. I also put the extremely low threshold (40th percentile) just for a custono would be selected if you are not using the WHERE clause.

  Subqueries are average in the last 30 days and the 40th percentile for 180 days before that. Let's take a look at custno = 5. There were two rows in the last 30 days (225 and 28 amounts), then the average in the last month is (225 + 28) / 2 = 253 / 2 = 126,5.
  Within 180 days prior to that, he had 7 amounts, in ascending order:
  1st (0th percentile): 647
  2nd (17th percentile): 1869
  3rd (33rd percentile): 3065
  4th (50th percentile): 7434
  5th (67th percentile): 8435
  6th (83rd percentile): 9393
  7th (100th percentile): 9712
  Since (for now), we are interested in the 40th percentile. It will be more than number 3065 (33rd percentile) and less than 7434 (50th percentile), 3065 to 7434, somewhat 40% being somewhat closer than 33% to 50%. This number turns out to be 4812.6.

• Complete list of "GPU features" in the standard Ps?

  Is there a complete list of that are all "features GPU" in Photoshop 13 Standard ?

  I had posted this in another thread, but I just move my request to this new thread:

  Chris Cox wrote:

  It will take place, but none of the GPU features (including 3D) will work...

  Is there a list or description of what are all these "Features GPU? It would be of great interest to all those who are stuck,temporarily or permanently- on such systems not supported, regardless of the platform.

  For example:

  

  It's on a maxed-out in all directions, unupgradeable MacBook on which 7.1 ACR hosted by Photoshop CS6 Standard works very well.

  I use Photoshop 13 Standard for ACR, and, frankly, I have not yet run within limits, although I realize they have to be without a doubt here.

  Hello

  Several features have support aid, so they calculate the CPU rather than the GPU use. If the feature will be present, just slower.

  I'm glad that the link was useful. I have not completely read through it, but saw that it was a bullet list.

  Kind regards

  Steve