PAST-PAlaeontological STatistics选首
Øyvind Hammer,D.A.T.Harper,P.D.Ryan
May21,2001
1Introduction
Welcome to the PAST!This program is designed as a follow-up to PALSTAT,an extensive package written by P.D.Ryan,D.A.T.Harper and J.S.Whalley(Ryan et
初中数学老师al.1995).It includes a number of functions which are commonly ud in palaeon-tology and palaeoecology.
The days,a number of large and very good statistics systems exist,including SPSS and Excel.Why yet another statistics program?
PAST is free.指甲上有竖纹是怎么回事
PAST is tailor-made for palaeontology.This means both that it includes
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functions which are not found in off-the-shelf programs(for example cladis-
tics,ordination and geometrical analysis),and that it does not include func-
tions which are of little u to palaeontologists and that only make the ur
interface more confusing.
PAST is easy to u,and therefore well suited for introductory cours in
quantitative palaeontology.
PAST comes with a number of example data ts,ca studies and exercis,
making it a complete educational package.
Further explanations of many of the techniques implemented together with ca histories are located in Harper(1999).
If you have questions,bug reports,suggestions for improvements or other com-ments,we would be happy to hear from you.Contact us at ohammer@ The PAST home page is
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2Installation
The basic installation of PAST is easy:Just download thefile’’and put it anywhere on your harddisk.Double-clicking thefile will start the program.The datafiles for the ca studies can be downloaded parately,or together in the packedfile’cafiles.zip’.Thisfile must be unpacked with a program such as WinZip.
We suggest you make a folder called’past’anywhere on your hard disk,and put all thefiles in this folder.
Plea note:Problems have been reported for some combinations of screen resolution and default font size in Windows-the layout gets ugly and it may be necessary for the ur to increa the sizes of windows in order to e all the text and buttons.If this happens,plea t the font size to’Small fonts’in the Screen control panel in Windows.We are working on solving this problem.
PAST also ems to have problems with some printers.Postscript printers from HP and Tektronix wor
kfine.
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3Entering and manipulating data
PAST has a spreadsheet-like ur interface.Data are entered in an array of cells, organized in rows(horizontally)and columns(vertically).
Entering data
To input data in a cell,click on the cell with the mou and type in the data.This can only be done when the program is in the’Edit mode’.To lect edit mode,tick the box above the array.When edit mode is off,the array is locked and the data can not be changed.The cells can also be navigated using the arrow keys.
Any text can be entered in the cells,but almost all functions will expect num-bers.Plea note the decimal point convention which has been chon by Windows depending upon your nationality:A comma(,)or a dot(full stop).’Dotted’data can be’commatized’from the Edit menu.Abnce/prence data are coded as0or 1,respectively.Any other positive number will be interpreted as prence.
The convention in PAST is that items occupy rows,and variables columns. Three brachiopod individuals might therefore occupy rows1,2and3,with their lengths and widths in columns A and B.Cluster analysis will always cluster items, that is rows.For Q-mode analysis of associations,samples(sites)should there-fore be entered in rows,while taxa(species)are in columns.For switching be-tween Q-mode and R-mode,rows and columns can easily be interchanged using the Transpo operation.
Commatize
Converts all full stops(’.’)in the data matrix to commas(’,’).This may be neces-sary for the program to read decimal points correctly,depending on your national-ity.
Selecting areas
重逢作文Most operations in PAST are carried only out on the area of the array which you have lected(marked).If you try to run a function which expects data,and no area has been lected,you will get an error message.
A row is lected by clicking on the row label(leftmost column).
A column is lected by clicking on the column label(top row).
Multiple rows are lected by lecting thefirst row label,then shift-clicking (clicking with the Shift key down)on the additional row labels.Note that you can not’drag out’multiple rows-this will instead move thefirst row (e below).
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Multiple columns are similarly marked by shift-clicking the additional col-umn labels.
The whole array can be lected by clicking the upper left corner of the array (the empty grey cell)or by choosing’Select all’in the Edit menu.
Smaller areas within the array can be lected by’dragging out’the area,but this only works when’Edit mode’is off.
Renaming rows and columns
When PAST starts,rows are numbered from1to99and columns are labelled A to Z.For your own reference,and for proper labelling of graphs,you should give the rows and columns more descriptive
but short names.Choo’Rename columns’or’Rename rows’in the Edit menu.You must have lected the whole array,or a smaller area as appropriate.
独立近义词Increasing the size of the array
By default,PAST has99rows and26columns.If you should need more,you can add rows or columns by choosing’More rows’or’More columns’in the Edit menu.When loading large datafiles,rows and/or columns are added automatically as needed.
Moving a row or a column
A row or a column(including its label)can be moved simply by clicking on the label and dragging to the new position.
Cut,copy,paste
The cut,copy and paste functions are found in the Edit menu.Note that you can cut/copy data from the PAST spreadsheet and paste into other programs,for ex-ample Word and Excel.Likewi,data from other programs can be pasted into PAST.
Remember that local blocks of data(not all rows or columns)can only be marked when’Edit mode’is off.
All modules giving graphic output has a’Copy graphic’button.This will place the graphical image in the paste buffer for pasting Word or Corel Draw. Remove
The remove function(Edit menu)allows you to remove lected row(s)or col-umn(s)from the spreadsheet.The removed area is not copied to the paste buffer.
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Grouping(coloring)rows
Selected rows(data points)can be tagged with one of ven attractive colors using the’Tag rows’option in the Edit menu.Each group is also associated with a symbol (dot,cross,square,diamond,plus,circle,triangle).This is uful for showing different groups of data ary and scatter plots and dendrograms.
Transpo
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The Transpo function,in the Edit menu,will interchange rows and columns.This is ud for switching between R mode and Q mode in cluster analysis,principal components analysis and riation.
Loading and saving data
The’Load’function is found in the File menu.PAST us an ASCIIfile format,for easy importing from other Word)and easy editing in a text editor. The format is as follows:
.columnlabel columnlabel columnlabel
rowlabel data data data
rowlabel data data data
rowlabel data data data
Empty cells(like the top left cell)are coded with a full stop(.).Cells are parated by white space,which means that you must never u spaces in row or column labels.’Oxford Clay’is thus an illegal column label which would confu the program.
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If any rows have been assigned a color other than black,the row labels in thefile will start with an underscore,a number from0to6identifying the color (symbol),and another underscore.
The’Inrt fromfile’function is uful for concatenating data ts.The loaded file will be inrted into your existing spreadsheet at the lected position(upper left).Other data ts can thus be inrted both to the right of and below your existing data.
Reading and writing Nexusfiles
The Nexusfile format is ud by many cladistics programs.PAST can read and write the Data(character matrix)block of the Nexus format.Interleaved data are not supported.Also,if you have performed a parsimony analysis and the’Parsi-mony analysis’window is open,all shortest trees will be written to the Nexusfile for further processing in other MacClade or Paup).
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