Version 5.0 (May 25th, 2020)

• OStats is now compatible with macOS Catalina.

Version 4.0.1 (June 10th, 2008)

• Removed Counts menu from Categorical window (since this was no longer supported).
• Fixed variable names in Two-Way Tables.
• Sheet windows (such as Residuals) on OS X now work when floating windows are present.
• Fixed bug with side-by-side dot plots (when changing continuous to categorical).
• Fixed bug with contour plotting scales.
• Fixed bug with two-way ANOVA when a variable had less than two groups.

Version 4.0 (March 28th, 2008)

• Added a global Colour menu under Edit. This gives a consistent colouring for the data table and across most of the plots. It can also be accessed by right-clicking on any plot that can be coloured. Continuous variables are shaded on a spectrum from green (low level) through black (medium level) to red (high level). Categorical variables are coloured with discrete colours.
• Many variable menus have been removed from plot windows since their functionality has been replaced by the colouring.
• Some plots include colouring for missing values: blue for continuous colouring and black for categorical colouring
• Tooltips have been added to many plots and options to give simple help on what they do.
• Clicking on a variable name in the data window twice will now sort in descending order.
• Box plots can now display notches - if the notches for two groups don't overlap then they are roughly different at the 5% level. (Note that this does not incorporate multiple comparisons.)
• Box plots can now have widths proportional to the square root of group size. This makes it easier to identify substantial differences.
• The Correlation window has been removed and the "Group:" menu on the Statistics window has been replaced by "By:". Choosing the "By:" variable to be continuous will then show correlation values if the main variable is continuous. If the main variable is categorical then a two-way table will be given, showing frequencies of the categories in the four quartile ranges of the continuous variable. (If the "By:" variable is categorical then the window behaves as for previous versions.)
• Categorical variables are now coloured in order of frequency by default.
• Since OStats 3.1, point jitter has been updated in a uniformly random manner. This has been replaced by random trajectories that move the points more smoothly.
• Added "Exponential" and "LS Exponential" to fit y = a e^{b x} to Bivariate Plots (the former directly minimizes sum of squared errors while the latter uses a linear least-squares fit to log-transformed data). Renamed "Direct" to "Power" in "Fit Curve" menu, for fitting the function y = a x^b. Fixed bug with prediction intervals not appearing for "LS Power" (or the new "LS Exponential").
• The 2D kernel density estimation in Bivariate Plots uses a new algorithm (thanks to Zdravko Botev). The "Histogram" option has been removed since you can obtain the same plot by making the kernel bandwidth very small.
• The Windows version now uses a Multiple Document Interface that automatically maximizes on launch. This seems more appropriate when you are using many OStats windows, in comparison to the previous behaviour.
• Improved display on Windows by reducing flickering when using dynamic features (such as changing bins, bandwidth, smoothing, etc.).
• Fixed bug with "Order by Mean" in Factor Plots.
• B-A plot and Link plot have been removed. A "link plot" can be obtained using the "parallel curve" option in Multivariate Plots. Removed several other plots that were rarely used, such as ogives, polygon plots, and pie charts.
• Fixed bug with Salavon Plot where you couldn't select an observation in the left pane.
• Added segmented bar charts to Categorical Plots. Colour the plot and then click on "Stack". The "Area Plots" give similar effects too.
• Group menu in Univariate Plots has become "Split". For dot plots, box plots and quantile plots you can now split by one categorical variable while colouring with another. (Note that you can use the same variable for splitting and colouring, and this gives different behaviour for box plots and quantile plots.)
• Large Numbers window can now be resized.
• More release notes to come...

Version 3.2 (October 24th, 2006)

• Confidence level selection has been redesigned. Instead of a floating window, the confidence level is now selected from Confidence in the Edit menu.
• The "order by mean" used by dot plots and effects plots can now be turned off. When off, the order of categories can be chosen using Order in the Edit menu.
• The size of points on a dot plot, scatter plot, effects plot and multivariate scatterplot can be set using the number keys, increased with the + key, or decreased with the - key.
• Added a Power window under Learn which demonstrates power curves for a one-sample t test.
• Most windows now use "live resizing", making visualizations in particularly easy to resize.
• Added alpha blending for points in dot plots and scatter plots to give a better sense of point density (Mac OS X only).
• A few extra transformations have been added.
• Fixed bug in Continuous Distributions that gave the wrong P-value for a negative t.
• Fixed bug in Continuous Distributions which prevented choosing certain degrees of freedom for the t distribution.
• Fixed bug in logistic regression when the response had only one option.
• Values for predictions in Regression no longer disappear when swapping between windows.
• Spearman correlation in matrix plot (under Multivariate Plots) now really shows Spearman correlation (not Pearson!).

Version 3.1 (17 October 2005)

• Jitter in Effects Plot and Dot Plot is now constantly random, to better show what is going on. That is, if you hold the mouse down and move around the jitter is regenerated constantly.
• Added Show Points option to Effects Plot. This uses jittered dots, as for Dot Plot. Jitter can be controlled by moving the mouse or using the scroll wheel (if available).
• More precise output of small P-values.
• Fixed "Copy Legend" for scatter plots.
• Fixed intermittent error in Fisher's exact test.

Version 3.0.4 (17 May 2005)

• Added regression through the origin to Bivariate Plots and Regression.
• Reinstated display of simple curve fit equations in Bivariate Plots.
• Enabled columns to get wider when resizing the data window.
• Other cosmetic fixes.

Version 3.0.3 (19 Apr 2005)

• Fixed a bug on Windows which caused problems with fitting power relationships.
• Improved behaviour of sheet windows on OS X.

Version 3.0.2 (22 Mar 2005)

• Added menus so you can now actually save and copy plots in the Windows version.
• Improved behaviour of colour legends.

Version 3.0.1 (15 Mar 2005)

• Fixed bug with drawing a Normal density on a histogram.
• Fixed bug with calculating residuals.

Version 3.0 (25 Feb 2005)

Version 3.0 includes extensive revisions to the interface, as well as many other changes. These changes include the following:

• Removed most sliders from plotting windows and replaced with the ability to drag on the plot to adjust the settings.
• Changed the Slice menu item to be a utility window. When one or more Slice windows are open, cases in the data window appear black if they match all of the slice conditions and grey if they do not.
• Changed behaviour of other windows to only use data that matches the slice conditions. For example, when you Copy the data you only get the cases in black.
• Added a Confidence menu item that gives a utility window for setting the confidence level. This replaces the separate popup menus that appeared on various windows.
• Added calculation of odds (in addition to proportions) under the Statistics menu.
• Added calculation of relative risk and associated inference under the Two-Way Tables menu.
• Changed layout of most windows so that menus for choosing variables are at the top and in the standard font size, with menus for options below each display and in a smaller font size.
• Revised "Salavon Plots" (under Two-Sample Plots). The circles are now drawn so they do not overlap each other. Squares can be plotted as well. The shapes can now be shaded blue in proportion to the value of another quantitative variable.
• Slice window/s for a data set now hide when a different data set is being explored.
• P-values are now displayed consistently through a single formatting function. This is currently set to display 4 decimal places, but could be made a preference.
• Display of significant figures is now consistent across different ANOVA tables.
• Added Signed-Rank distribution to Discrete Distributions plot. Made parameter controls for discrete distributions more uniform. Improved calculation of signed-rank and Wilcoxon distributions (so now can plot Wilcoxon for up to n_A = n_B = 15, rather than previous 7).

Version 2.1.1 (26 Oct 2004)

This is a minor update to Version 2.1.

• Corrected calculation of P-value for one-sided sign test.
• Corrected calculation of confidence interval for difference between two proportions when pooling the sample proportions.

Version 2.1 (7 May 2004)

Version 2.0.1 (15 Aug 2003)

• Added Paste Special item to Edit menu. This currently has one option, the ability to paste Nokia ringtones in RTTTL format.
• Fixed major bug which caused saved plots to always be blank, as well as some other minor bugs.

Version 2.0 (30 Jul 2003)

This major release contained a large number of new features, as well as a rearrangement of the menus, particularly Visualise, to make it faster to explore data in multiple ways.

Detailed documentation of the new version will be available in late August.

Version 1.1.4 (12 Nov 2002)

• Replaced existing methods for calculating residuals by a menu item, Residuals, under the Edit menu. Now when you are in any of Regression, Continuous, Compare Groups, or Multiple Regression, you can select Residuals to bring up a menu for creating residuals. In addition to the name of the new variable, you can choose whether to have Unstandardized, Standarized, or Studentized residuals calculated.
• Added Type, under Edit, to allow you to force OStats to consider a variable to be categorical. By default, any variable consisting of numbers will be considered quantitative, even if it only has a few values. Currently you may need to reopen other windows with plots and statistics for the change to be effective.
• Added indicator variables to the available predictors in Multiple Regression. For example, Eyes:Brown is the variable that is 1 when the categorical variable Eyes is Brown, and 0 otherwise.
• Added Multiple Regression under Analyse, replacing Logistic Regression. When the selected response is categorical, this carries out logistic regression (as before), while when the response is quantitative, it carries out multiple regression (an extension of least-squares fitting).
• Rearranged items in the Analyse and Learn menus so that they are in a more logical order.
• Added vertical scroll bars to all text fields. This fixes a problem for people using large fonts.
• Added calculation of Spearman correlation, under Correlation.
• Improved interface to Principle Components, allowing you to specify which variables you want to use. This can be a useful technique for seeing which variables are important.

Version 1.1.3

• Added Two-Way ANOVA under Analyse. This performs a simple two-way ANOVA for balanced designs only. It allows you to specify whether factors are fixed or random.
• Added the option of error bars to Effects Plot when plotting main effects. These can show 95% intervals based on individual standard deviation, pooled standard deviation, or Tukey's HSD.
• Added Tukey's HSD intervals to the CI panel in Compare Groups.
• Added the Studentized Range distribution to Continuous Distributions under Learn. Click on the Q panel. Currently no plot is available.
• Added a "Slice" facility to Statistics, useful for getting statistics on the relationship between a variable and two other categorical variables.
• Fixed the presentation order of categories to be more consistently by counts in descending order.
• Added the calculation of exact confidence intervals for binomial proportions.

Version 1.1.2 (7 Oct 2002)

• Added Circular Plot for displaying directional data. Circular dot plots, density plots, and histograms can be generated.
• Added Density Plot 2D for showing the density of bivariate data. This can display 2D histograms (where black is maximum frequency) or a simple kernel estimate (as used in Density Plot).
• Clicking on a point in a scatter plot, dot plot, vector plot, or circular plot will now highlight the corresponding record/s in the data set.
• Categorical variables which are numeric are now displayed in their natural order.
• Added confidence level menu to Continuous.
• Added analysis of odds ratios through the OR panel of Two-way Tables.
• Substantial additions to Weibull Plot and Reliability, including new models, interactive parameter changing, probability plots, and bootstrap and jackknife analysis.

Version 1.1 and 1.1.1 (August 2002)

• Numerical variables with 10 or fewer values can now also be used as categorical variables.
• Added a "Vector Plot" for displaying a number of quantitative variables using barycentric coordinates.
• Added a Pair Plot to give a nonparametric comparison between two distribution.

Version 1.0.5 (29 May 2002)

• Added the generation of multiple confidence intervals to Compare Groups. This can use error rates on an individual basis or using the Bonferroni adjustment for a family error rate.
• Added a Combine item under Edit to allow new variables to be created by adding, subtracting, multiplying, or dividing pairs of existing variables.
• Added Transform menu to make new variables using a variety of transformations. The "Transform" options which were available under Analyse have now been removed, under the assumption that if you are serious about a transformation then you will create a new variable. The "Transform" options are still available under Visualise to allow rapid exploration.
• Included "Rank" under Transform to give the ranks of the observations when put in order.
• Included "Standard" under Transform to give the standardised scores (subtracting the mean and dividing by the standard deviations) for the observations.
• Added polynomial regression to Scatter Plot and Regression. In the plot you can show linear, quadratic, cubic, or quartic fits, including confidence and prediction intervals. In the analysis you now get a table with standard errors, t-scores, P-values, and confidence intervals for each coefficient.
• Split the Regression analysis into three panels, one for the fitted function, one for making predictions, and one for ANOVA.
• Revamped Categorical analysis, as for Two-way Tables, so you can see the relationship between a chi-square test and a one-sample test of proportion, using a menu to specify that the hypothesised proportion should be used for the standard error.
• Revamped Two-way Tables analysis. There are now two panels so you can do a chi-square test or a two-sample comparison of proportions (if appropriate). Previously if there were two groups it would only show the proportion test. Now you can see the relationship between the two methods, using a menu to select pooled proportions.
• Reintroduced Weibull Plot and Reliability analysis. These are rather specialised but may be of general interest.

Version 1.0.4 (22 Apr 2002)

• Added Polygon Plot, a useful alternative to Histogram for comparing distributions.
• Added standardised histograms option to Histogram (in which area equals proportion).
• Added the ability to specify a variable containing note durations to Time Plot, as well as an option to prevent scaling of the values into a standard range. This allows OStats to play simple tunes (using the standard MIDI pitch values).
• Added correlograms and variance plots to Time Plot for visualising dependencies in the data.

Version 1.0.3 (5 Apr 2002)

• Extended interface in Slice to allow the selection of more than one group, a logical "Or" operation though still with only a single variable. (You can do a logical "And" by making a series of slices.)
• Add Observation to create a new variable which simply gives the observation number within the data set. This is handy for making time plots when you didn't record a time variable, necessitated by the following change.
• Removed the automatic inclusion of an "Observation" variable everywhere. This was rather artificial and had some problems, such as not being sorted when the rest of the data was sorted. You must now record your own time variable or use the Observation command.
• Added Time Plot for working with time plots. These were previously done using Scatter Plot (making the horizontal variable time) but there are many things that are specific to time plots which warranted a separate window. These include the ability to play the time series as music (if you have QuickTime) as well as correlograms and variance plots for looking at the time dependencies.
• Added the ability to join points in Scatter Plot (under Fit) to enable simple time plots. However, you should really use the new Time Plot for these.
• Added Indexed Plot for comparing a continuous variable split into two groups using an index variable. For example, this could compare measurements made by two people on different days (the index).
• Added the generation of Random Numbers (under Learn), with normal distributions, uniform distributions (including integer values and sums of uniform variables), and exponential distributions.
• Added the generation of Noise (under Learn) of varying colours (white, pink, and brown), discrete or continuous. This is useful in conjunction with the Play button on the Time Plot.
• Added more statistics (Min, Max, IQR) for continuous variables to Statistics.
• Added Split, allowing the exploration of frequencies of a continuous variable above and below a specified value. A new binary variable can then be created based on this split.
• Improved display of one-dimensional clusters in Dot Plot.
• Added Name (under Edit) to create a variable which gives names to the observations. These are used by Magritte.
• Added Integer option to Histogram for display discrete variables. This will be available if all numbers are integers and the range of values is less than 40.
• Added an option to Histogram to either display counts or frequencies.

Version 1.0.2 (21 Mar 2002)

• Improved Scatter Plot for making times series comparison between groups (as required for STAT1201 Project 1).
• Added Dialogue menu. Documentation on this menu will be available soon. (The Isabelle option will only ever work under Mac OS X.)
• Added one-dimensional clustering to Dot Plot using k-means. This is not really useful for anything in itself but it is used by Magritte.
• Added plotting of median and quartiles (a mini box plot) to Dot Plot.

Version 1.0.1 (15 Mar 2002)

• Added ability to show conditional proportionals in two-way tables using Statistics under the Summarise menu.
• Fixed memory shortage in Mac OS 8-9.
• Fixed percentile calculations (which included the median).
• Minor interface tweaks.
• Renamed the Mac OS X version "OStatsX" and the Mac OS 8-9 version "OStats".

Version 1.0 (11 Mar 2002)

• Added tools for carrying out logistic regression. The Logistic Plot (under Visualise) shows the logistic fit for single variable regression, including showing several regressions for different groups. Logistic Regression (under Analyse) does full single and multiple regression, giving parameter estimates, tests of significance, and odds ratios for binary variables. Interaction terms can be added by selecting multiple rows and clicking "Add Interaction" (Mac only).
• Clicking on a case in a Star Plot now highlights the case in the plot and in the data window. You can also select a case in the data and it will be highlighted in the plot. This will be extended in version 1.1 to allow you to track cases across different plots.
• Added Chernoff faces as an option under Star Plot. These use values of multivariate data to draw faces, giving an interesting representation of the data and a useful tool for detecting unusual individuals or groups. (Currently there is no way to identify which variable corresponds to which facial feature. This will be added soon.)
• Added Copy Legend under Edit to allow copying of legends displayed with certain plots. To copy a plot with its legend, first use Copy to copy the plot, paste it in the destination, then return and use Copy Legend
• Added plotting by Slice option for scatter plots. For categorical variables, a slice only plots those points coming from a specified group. For continuous variables, a slice uses brightness to indicate which points have values close to a specified value. This value can be moved dynamically to move through an extra dimension.
• Removed plotting by symbols from scatter plots and normal plots. These had been added for a particular purpose but now sit uneasily with the rest of the plots. A more consistent approach to plotting by symbols will be added in a future version.
• Added quantile-quantile plots
• Added star and profile plots for exploring multivariate data.
• Added pie charts split by groups.
• Added Scatter Plot Matrix.
• Removed correlation matrix plot. Correlation under the Summarise menu now gives a table which can be copied. The Scatter Plot Matrix shows a graphical representation of the correlation values, similar to the previous correlation matrix plot.
• Added Scatter Plot 3D.
• Various cosmetic changes, especially for Windows version.

Version 0.9 (26 Nov 2001)

• The Distributions item under Learn now draws probability distributions for Binomial. Click on the bars to select and find the probabilities under them. Shift-click to remove the selection.
• The Wilcoxon rank-sum distributions (for n_A ≤ 7 and n_B ≤ 7) are included under Distributions.
• Chi-square and F are included under Distributions.
• A crude demonstration of the effect of an outlier on the least-squares line is available under Learn.
• The Correlation matrix now shows the results of a significance test (against population correlation = 0) using green dots. (One dot for P-value between 0.1 and 0.05, two for between 0.05 and 0.01, and three for below 0.01.)
• Pie Chart has been added under Visualise but it currently will not split pie charts into groups.
• Bar Charts can now be displayed horizontally. This is useful for large numbers of categories.

Version 0.8 (3 Oct 2001)

• Bar Chart has been added for visualising categorical data. The bars can be split by another categorical variable, showing either raw counts or conditional proportions.
• Histograms can now be split by a categorical variable. If there are too many groups then only the most common groups are displayed. (Make the window taller to see more groups.)
• The Categorical item under the Analyse menu now works. Use it to do one-sample proportion tests and one-dimensional chi-square tests. For the latter, enter the hypothesised proportions under the Probability column.
• You can store residuals from Regression or ANOVA. These appear as a new column in your data and you can then visualise them using the standard tools. (They won't be saved with your data.) Clicking on a residual will highlight the whole row, so you can easily examine unusual ones.
• Clicking on the title of a continuous variable's column now sorts the data numerically by that variable. (Previously it treated numbers alphabetically.) This is useful for dealing with outliers.
• Sample now allows you to choose from a range of sample sizes, rather than forcing a full resample.
• Extensive speed improvements have been made throughout.

Version 0.7 (10 Sep 2001)

• Effects Plot has been added for use in STAT1201 Practical 2.
• A scatter plot against observation number (a time plot) will now split colours into separate sequences. Fits to the data are also done separately for each group.
• A legend is displayed when colour or symbols are used in a plot. (The legend is not currently copied when copying the plot.)
• Pasting now works if the first line is blank.
• Decimal places are displayed more intelligently when getting statistics or calculating confidence intervals.
• Proportions can now be displayed in Statistics for categorical variables.
• Probability calculations are now accessed through Distributions under the Learn menu.
• Data can be pasted using the standard Paste item under Edit, as well as with New > Clipboard. The various other New options are now under Edit as well.