GFDI 0 Posted April 4, 2006 I am working with starting point and endpoint survey data based on UTM NAD83 that is in meters. I wanted Rockworks to plot the petals using length(distance in meters) as the petal radius. There is generally more than one measurement within any given petal interval using 10 or 5 degree petal widths. The largest distance when using the measure distance or compute distance option in Rockplot2D gives 500, but even if I manually add up all the distances that fall into that petal width I still only come up with about 271.5m. These distances are the ones from the lineation computation option in RockWorks v2004 and have been checked with another program. Is there anyway I can get the distances to compute properly? The other thing I wish to ask is for definitions of a some of the statistical answers given in the rosediagram legend. What does Maximum Percentage, Mean Percentage and R-mag tell me? How is the Standard Deviation being calculated? Thank you for your time. Share this post Link to post Share on other sites

Mitch 0 Posted April 5, 2006 The Length's are proportional and don't represent the actual cumulative length for that petal. The maximum petal length will always be 500 because that's the arbitrary size of the digram. The labels for the circles are in percent. Maximum Percentage: the largest petal by percent in the sample group. Mean Percentage: The mean percentage of all non-zero petals. R-Mag: Resultant of the vector mean. Data set with a large dispersion will have a small resultant. The resultant is standardized from a range of 0 to 1. Standard Deviation: Its actually the standard error of the vector mean whcih is a bit different then a standard deviationand is used to define the Confidence Interval. Se = 1 / SQRT ( n * R * k ) k is a concentration parameter Share this post Link to post Share on other sites