Most authors generated their test clusters using Milligan's algorithm (well cited paper,Milligan, G.: An algorithm for creating artificial test clusters. Psychometric 50 (1985) 123–127). And A public domain implementation of this algorithm is available from Dave Dubin (Dubin, D.: clusgen.c. http://alexia.lis.uiuc.edu/ ̃dubin/ (1996)). However, this link is not available. Could you please tell me if there is any other implementation of this algorithm or other ways to generate artificial test clusters? Thanks in advance!
You may want to consider using MixSim in R or CARP in C which is considered to be some sort of a modern gold standard for assessing clustering. CARP appears to be more flexible. You can get the R package from CRAN, and the C package from MLOSS
Hope this helps!
Related
Say I have a URL like https://www.science.org/doi/10.1126/science.abb4363, how can I get the full citation as:
#article{
doi:10.1126/science.abb4363,
author = {Sergio Almécija and Ashley S. Hammond and Nathan E. Thompson and Kelsey D. Pugh and Salvador Moyà-Solà and David M. Alba },
title = {Fossil apes and human evolution},
journal = {Science},
volume = {372},
number = {6542},
pages = {eabb4363},
year = {2021},
doi = {10.1126/science.abb4363},
URL = {https://www.science.org/doi/abs/10.1126/science.abb4363},
eprint = {https://www.science.org/doi/pdf/10.1126/science.abb4363},
abstract = {There has been much focus on the evolution of primates and especially where and how humans diverged in this process. It has often been suggested that the last common ancestor between humans and other apes, especially our closest relative, the chimpanzee, was ape- or chimp-like. Almécija et al. review this area and conclude that the morphology of fossil apes was varied and that it is likely that the last shared ape ancestor had its own set of traits, different from those of modern humans and modern apes, both of which have been undergoing separate suites of selection pressures. Science, this issue p. eabb4363 A Review describes the unique and varied morphologies in fossil and modern apes, including humans. Humans diverged from apes (chimpanzees, specifically) toward the end of the Miocene ~9.3 million to 6.5 million years ago. Understanding the origins of the human lineage (hominins) requires reconstructing the morphology, behavior, and environment of the chimpanzee-human last common ancestor. Modern hominoids (that is, humans and apes) share multiple features (for example, an orthograde body plan facilitating upright positional behaviors). However, the fossil record indicates that living hominoids constitute narrow representatives of an ancient radiation of more widely distributed, diverse species, none of which exhibit the entire suite of locomotor adaptations present in the extant relatives. Hence, some modern ape similarities might have evolved in parallel in response to similar selection pressures. Current evidence suggests that hominins originated in Africa from Miocene ape ancestors unlike any living species.}}
I was able to download the citation by visiting the link manually, but are there any programmatic APIs to convert a URL (like even a Wikipedia URL) into a formal citation? If not, I am not sure what is the recommended approach to getting these efficiently.
So as of yet, I am not profficient in programming.
I am writing a paper in mathematics and obtained different results from the GeoGebra min function and algebraical methods.
I am sure that the algebraical methods are correct, but I really want to know why the min function was faulty.
The result from the algebra was an interval between 1010 and 1011.
From GeoGebra I got a single point as a solution (1010.15898).
If you could explain to me why GeoGebra ommits all of these other solutions, I would be very thankful.
I would also appreciate if someone could direct me to the math behind the function, so I could include it in my paper and discuss its' relevance.
Thanks in advance!
GeoGebra is using a modification of the (local) optimization algorithm given in Richard Brent, Algorithms For Minimization Without Derivatives, Prentice-Hall, Inc. 1973.
See the source code for more information.
What are all the factors one should consider in order to compare 3 formal verification tools?
Eg: Jaspergold, Onespin, Incisive.
From my little research, Jaspergold comes on top. But i want to do it myself on a project.
I have noted down some points such as
1.Supported languages(vhdl, sv, verilog, sva, psl,etc)
2.GUI
3.Capability(how much big design can they handle)
4.Number of Evaluation cycles
5.Performance(How fast they find proof or counter example)
With what other features can i extend this list?
Thanks!
What good naming conventions do you use for PLC?
I've seen hundreds of projects from different programmers, dozens of companies standards, RA, Beckhoff posted in some documents their naming... dozens of different ideas.
For years, naming tags was one of the most difficult task for me. You can't imagine discussion when I ask a student to create a bit. It's like being the hardest thing on Earth :) (usually, after creating a_bit and another_bit, inspiration is gone).
I asked for RSLogix 5000 because I found it most flexible, having tags, alias, scope tags, descriptions(stored in CPU for latest versions).
Have some tips to share that you find suitable for your use?
Naming tags should have a refrence to the real world. A recent example I did was this:
PTK3KOS1
Pressure Transmitter Kettle 3 Kettle Overhead Solvent #1
This is the tag used in the CMMS system (Maintenance system), and the P&ID
I use UDT's in RSL5K, so that becomes the following in RSLogix:
PTK3KOS1.VAL (Current value)
PTK3KOS1.MIN (I use this especially when I use flex I/O for scaling)
PTK3KOS1.MAX (And I also use it to pass min/max values to some HMI's like WW)
PTK3KOS1.LFF (Signal fault)
PTK3KOS1.LLA (Low alarm bit)
PTK3KOS1.LLL (Low Low bit)
PTK3KOS1.LHA (Hi Alarm bit)
PTK3KOS1.LHH (Hi Hi Bit)
PTK3KOS1.SLA (Setpoint low alarm)
PTK3KOS1.SLL
PTK3KOS1.SHA
PTK3KOS1.SHH
The most common system is the ISA system, see
http://www.engineeringtoolbox.com/isa-intrumentation-codes-d_415.html for an example.
There is also the KKS system, which I personally believe was designed by masochists, and will only use it when forced to do so.
http://www.vgb.org/en/db_kks_eng.html
I like to use some thing like this:
aabccdd_eeee_human-readable-name_wirenumber
aa
DO=Digital Output
DI=Digital Input
AO=Analog Output
AI=Analog Input
gl=Global variable
co=constant
pt=produced Tag
ct=consumed Tag
b
Rack Number
cc
Slot
dd
address 0-64
eeeee
panel/drawing tag
DO10606_MA949_WshLoaderAdvance_9491
Does System C support tri-state logic? That is, bits that can get 0, 1 or X, where X means "unknown"?
If it does, does it also support vectors that can contain Xes, including logic and arithmetic operations?
Here is what you need:
http://www.asic-world.com/systemc/data_types2.html
http://en.wikipedia.org/wiki/SystemC#Data_types
It does not have tri-state variables, but quad-state (is that correct? :P) variables (0,1,X,Z). More about it in the above links. It also supports vectors of those variables.
Hope I helped you a little bit :)
Yeah, you're looking for the sc_logic and sc_lv types which are 4 state variables: 0, 1, X, and Z. Pay attention to how they interact when you resolve them together. There's a nice tables on the asic-world.com site taken directly from the SystemC User Manual.
Note though that this doesn't work like in Verilog where X can also act as a wildcard. I had to build my own function to add that functionality.