FYI,I have googled well, but couldn't find any clear way.
I have drawn a flowchart in MS visio. How to generate pseudocode from it?
Is there any way in visio or any other software to do that?
Pseudocode:
start
Declare wholesalePrice as Integer
Declare retailPrice as Integer
Declare profit as Integer
string END_LINE = “”
Call housekeeping()
Call detail()
Call endOfJob()
stop
housekeeping()
output “Enter the wholesale price”
input wholesalePrice
return
detail()
output “Enter the retail price”
input retailPrice
profit = retailPrice - wholesalePrice
output profit
return
endOfJob()
output “Thanks for using this program”
Related
Motivation
Modelica does store units of measurement (e.g. SI units and Non-SI units) as an attribute with regard to a variable. Here is an example for a Non-SI-unit:
type Time_months = Real( quantity = "Time", unit = "mo", displayUnit = "months" )
Since for models in economics it will be rather akward to give rates in seconds, I would like to write a rather general unit conversion function that will allow to convert units of time. So ideally a function to convert to another time base should work with three inputs and one output:
input Real timeValue "the value of time to be converted";
input String timeBaseA "the time base for timeValue, e.g. \"mo\" ";
input String timeBaseB "the time base to convert to, e.g. \"yr\" ";
output Real convertedTimeValue "the result of the conversion";
Questions
If we assume that a variable for some time value already has a specific unit attribute (e.g. "mo") it would make sense to use that meta information within a model.
Question 1: How can meta information like unit be accessed within a model?
Ideally something like the following would be great:
String timeBaseA := timeValue.unit;
or
String timeBaseA := getUnit( timeValue ) "some function to read unit information";
Question 2: How can meta information like unit be assigned within a function?
In the example we would of course like to return the output value with the correct unit of time. So ideally we would like to have:
output Real convertedTime( quantity = "Time", unit = strTimeBaseB )
Unfortunately, using an input will give rise to an error as the variability is different: The unit attribute should have constant variability but the input variable has parameter variability. (Using a function - which would be nice - also fails for the same reason.)
Regarding Question 1:
I have never used Wolfram SystemModeler, but the Modelica Language Specification 3.4 says in chapter 4.8 (Predefined Types and Classes):
The attributes of the predefined variable types (Real, Integer, Boolean, String) ... cannot be accessed using dot notation, and are not constrained by equations and algorithm sections.
Regarding Question 2:
I think it is only possible to define the unit of a variable on declaration from a literal or from a final parameter - at least this is what I observed in Dymola.
Alternative - use operator records
You could use operator records for your task. This will allow you to store the time in seconds and convert it to what ever needed when the value comes to use.
Operator records allow you to define several function to create them, compare or add them, convert to String, etc.
See the brief example below, where a operator record Time is defined, which can be created with two different constructor functions from seconds or days and can be converted to Strings with day or seconds
operator record Time
Integer s "Second";
encapsulated operator 'constructor'
import Time;
function from_s
input Integer s "Seconds";
output Time t(s=s);
algorithm
end from_s;
function from_d
input Integer d "Days";
output Time t(s=d*24*3600);
algorithm
end from_d;
end 'constructor';
encapsulated operator 'String' "Convert Time to string"
import Time;
function formated
input Time t;
input String format = "s" annotation(choices(choice="s" "seconds", choice="d" "days"));
output String str;
algorithm
if format == "d" then
str :=String(t.s/24/3600);
else
str :=String(t.s);
end if;
end formated;
end 'String';
encapsulated operator function '==' "Compare time records"
import Time;
input Time t1;
input Time t2;
output Boolean result "= t1 == t2";
algorithm
result := t1.s == t2.s;
end '==';
end Time;
Usage:
import Modelica.Utilities.Streams.print
t1 = Time(d=12) // create record using day constructor
t2 = Time(s=3600*24*2) // create record using second constructor
print(String(t1, format="s")) // prints 1036800
print(String(t1, format="d")) // prints 12
print(String(t2, format="s")) // prints 172800
print(String(t2, format="d")) // prints 2
See Modelica Spec 3.4 Chapter 14 "Overloaded Operators" for details.
Note: This was tested with Dymola 2019, not with Wolfram SystemModeler
In Modelica usually every variable is computed based on SI units. Then you have displayUnits to plot them in a different unit (not affecting the actual computation).
I don't know about SystemModeler, but in Dymola the conversion between the unit (of computation) and the displayUnit (only for plotting) is handled by a pre-defined script (displayUnit.mos). It can be extended by the user to contain custom displayUnits. The code for the display units related to time is shown below. I extended it to have week (w) additionally to the predefined ones.
// Syntax:
// defineUnitConversion(<unit>, <derived unit>, <scale>, <opt. offset>);
// Time
defineUnitConversion("s", "ms", 1000);
defineUnitConversion("s", "min", 1/60);
defineUnitConversion("s", "h", 1/3600);
defineUnitConversion("s", "d", 1/86400);
defineUnitConversion("s", "w", 1/604800);
This can then be selected in plots manually or as the default ´displayUnit´ via Modelica.SIunits.Time t(displayUnit = "w") = ...;
The disadvantage is, that this extension has to be done in a file in the install directory. So it has to be changed again after re-installing the tool or when using a different computer.
If there are numerical reasons to not compute solutions in seconds (e.g. because values would get to big), the solution would be the nominal attribute, which enables a scaling of the variables.
BTW: I think months are not a very good unit of time as they can have 28 to 31 days. That's why I chose weeks in my example.
You could use conversion like is done in the MSL, for example the function Modelica.SIunits.Conversions.to_degC which has the signature:
function to_degC
input Temperature Kelvin "Kelvin value";
output NonSIunits.Temperature_degC Celsius "Celsius value";
end to_degC;
This works, but you need one such function for each unit you want to convert between (which is why most calculations are done using SI-units).
I am well aware that one is able to assign a value to an array or constant in Swift and have those value represented in different formats.
For Integer: One can declare in the formats of decimal, binary, octal or hexadecimal.
For Float or Double: One can declare in the formats of either decimal or hexadecimal and able to make use of the exponent too.
For instance:
var decInt = 17
var binInt = 0b10001
var octInt = 0o21
var hexInt = 0x11
All of the above variables gives the same result which is 17.
But what's the catch? Why bother using those other than decimal?
There are some notations that can be way easier to understand for people even if the result in the end is the same. You can for example think in cases like colour notation (hexadecimal) or file permission notation (octal).
Code is best written in the most meaningful way.
Using the number format that best matches the domain of your program, is just one example. You don't want to obscure domain specific details and want to minimize the mental effort for the reader of your code.
Two other examples:
Do not simplify calculations. For example: To convert a scaled integer value in 1/10000 arc minutes to a floating point in degrees, do not write the conversion factor as 600000.0, but instead write 10000.0 * 60.0.
Chose a code structure that matches the nature of your data. For example: If you have a function with two return values, determine if it's a symmetrical or asymmetrical situation. For a symmetrical situation always write a full if (condition) { return A; } else { return B; }. It's a common mistake to write if (condition) { return A; } return B; (simply because 'it works').
Meaning matters!
I am doing a small script to get SNMP traps with PySnmp.
I am able to get the oid = value pairs, but the value is too long with a small information in the end. How can I access the octectstring only which comes in the end of the value. Is there a way other than string manipulations? Please comment.
OID =_BindValue(componentType=NamedTypes(NamedType('value', ObjectSyntax------------------------------------------------(DELETED)-----------------(None, OctetString(b'New Alarm'))))
Is it possible to get the output like the following, as is available from another SNMP client:
.iso.org.dod.internet.private.enterprises.xxxx.1.1.2.2.14: CM_DAS Alarm Traps:
Edit - the codes are :
**for oid, val in varBinds:
print('%s = %s' % (oid.prettyPrint(), val.prettyPrint()))
target.write(str(val))**
On screen, it shows short, but on file, the val is so long.
Usage of target.write( str(val[0][1][2])) does not work for all (program stops with error), but the 1st oid(time tick) gets it fine.
How can I get the value from tail as the actual value is found there for all oids.
Thanks.
SNMP transfers information in form of a sequence of OID-value pairs called variable-bindings:
variable_bindings = [[oid1, value1], [oid2, value2], ...]
Once you get the variable-bindings sequence from SNMP PDU, to access value1, for example, you might do:
variable_binding1 = variable_bindings[0]
value1 = variable_binding1[1]
To access the tail part of value1 (assuming it's a string) you could simply subscribe it:
tail_of_value1 = value1[-10:]
I guess in your question you operate on a single variable_binding, not a sequence of them.
If you want pysnmp to translate oid-value pair into a human-friendly representation (of MIB object name, MIB object value), you'd have to pass original OID-value pair to the ObjectType class and run it through MIB resolver as explained in the documentation.
Thanks...
the following codes works like somwwhat I was looking for.
if str(oid)=="1.3.6.1.2.1.1.3.0":
target.write(" = str(val[0][1]['timeticks-value']) = " +str(val[0][1]['timeticks-value'])) # time ticks
else:
target.write("= val[0][0]['string-value']= " + str(val[0][0]['string-value']))
In our model of a physical system, we modify one flux value by a factor from a look-up table. The LUT itself is selected from a catalog of LUTs based on an integer index. We're currently loading the table data into CombiTable2D components. What is the correct way to select/define the correct LUT? If we have them all as named tables in one input data file, is there a way to pick an LUT based on it's tableName (the CombiTable parameter)? I've been playing with For loops in either equation or algorithm formats, but haven't found a syntax that works yet.
Thanks in advance for the thoughts...
I think it only works with one table per file so you can have an array of tables, something like:
parameter Integer N = 3;
parameter String selectTable = "tab2";
Modelica.Blocks.Tables.CombiTable2D tableArray[N](
each tableOnFile = true,
fileName = {"file1", "file2", "file3"},
tableName={"tab1", "tab2", "tab3"});
// use the tableArray
for i in 1:N loop
// note that N and selectTable need to be known at compile
// time so that the if and the for loop can be expanded
if (tableArray[i].tableName == selectTable)
then
connect(tableArray[i].u1, u1);
connect(tableArray[i].u2, u2);
connect(tableArray[i].y, y);
endif;
end for;
I would like to use a dataset filename "AUDUSD" in several functions. It would be easier for me, just to change the filename "AUDUSD" to a more general name like "FX" and then using the abbreviation "FX" in other_matlab functions, e.g. double(). But matlab does not know the name "FX" (that should be assigned to the dataset "AUDUSD") in the code below... Any suggestions?
CODE:
FX = 'AUDUSD';
load(FX); %OKAY !!! FX works as input to open file AUDUSD!
Svars = {'S_bid','S_offer'};
Fvars = {'F_bid','F_offer'};
vS = double(FX,Svars); % FX does NOT work as input for the file AUDUSD
There is no double() function that accepts multiple cell arrays as arguments (this is what happens when you call double(FX,Svars)).
If you call double(FX), then each character in FX is interpreted for its ASCII value and then cast to double. So you get [ 65.0 85.0 68.0 85.0 83.0 68.0 ]. This is the behavior for the double() function if you provide a vector: each individual value in the vector is cast to double.
You'd have to provide more details on what you're trying to accomplish to give any more suggestions.
I have a different example, maybe you will better understand my point. The key work I would like to process is as follows:
I have got a folder with "dataset" files. I would like to loop through this folder, entering in any datasetfile, extracting the 2nd and 3rd column of each dataset file, and constructing only ONE new datasetfile with all 2nd and 3rd columns of the datasetfiles.
One problem is that the size of the datasetfiles are not the same, so I tried to translate a datasetfile into a double-matrix and then consolidate all double matrices into ONE double matrx.
Here my code:
folder_string = 'Diss_Data/Raw';
FolderContent = dir(folder_string);
No_ds = numel(FolderContent);
for i = 1:No_ds
if isdir(FolderContent(i).name)==0
file_string = FolderContent(i).name;
file_path = strcat(folder_string,'/',file_string)
dataset_filename = file_string(1:6);
load(file_path); %loads the suggested datasetfile; OKAY
M = double(dataset_filename);% returns an ASCII code number; WRONG; should transfer the datasetfile into a matrix M
vS = M(:,2:3);
%... to be continued
end
end