Attempting to use the docs to understand a node function - node.js

I'm attempting to understand the code in conjunction with http://nodejs.org/api/util.html and here's what I understand with regards the code shown below
var util = require('util');
Includes the util module.
Which has some effect in the code shown below,
var financeurl = function(symbols, columns) {
return util.format(
'http://finance.yahoo.com/d/quotes.csv?s=%s&f=%s',
symbols.join('+'),
columns);
};
The second line where it says, and the three lines that follow it
return util.format
The node documentation says,
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
util.format(format, [...])#
Returns a formatted string using the first argument as a printf-like format.
The first argument is a string that contains zero or more placeholders. Each placeholder is replaced with the converted value from its corresponding argument. Supported placeholders are:
%s - String.
%d - Number (both integer and float).
%j - JSON.
% - single percent sign ('%'). This does not consume an argument.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
'http://finance.yahoo.com/d/quotes.csv?s=%s&f=%s',
is the first argument which is to be returned as a formatted string. It contains zero placeholders. Am I correct?
I'm somewhat lost with the next part, do 'symbols' and 'columns' come from node? Should I search elsewhere in the script for them? What I suspect they do is take the symbols of specific stocks and join, concatenate them to different columns.
Is my interpretation of the code with reference to the docs in someway correct?

Node's util.format() is a Variadic function - it takes a variable number of arguments.
The documentation specifies that the first parameter is a string template containing zero or more special placeholders. The remainder of the arguments are treated basically as an array and placeholders in the string template are filled in with these values and the resulting string is returned.
The string in the example - http://finance.yahoo.com/d/quotes.csv?s=%s&f=%s contains two placeholders - both %s near the end of the string. In the code given, the first placeholder is replaced with the value of symbols.join('+') and the second with the value of columns.
(join() is a built in JavaScript method on Array that produces a String consisting of the toString() value of each element of the Array separated by default by a comma, or the provided String argument('+' in this case).)
symbols and columns do not come from Node - they are variables provided elsewhere in the program. You are correct in guessing that symbols contains the stock ticker symbols you're going to query the Yahoo Finance service with, but columns actually specifies the data columns that you want back from the service. (The values you can provide for columns and what they mean are described at the top of the program in a comment. As for how I know this... I'm taking the Startup Engineering course too... :D )
You're basically building up a URL for a request against the Yahoo Finance REST service - you can play around with it yourself and see what the program's getting from it by plugging in values in that string template -
http://finance.yahoo.com/d/quotes.csv?s=GOOG&f=snj1pr - gives you a CSV of containing a bunch of different values for GOOG - Google's stock symbol.
http://finance.yahoo.com/d/quotes.csv?s=GOOG+AAPL+MSFT&f=sp - gives you a CSV of just the stock ticker symbol and the price-per-share of Google, Apple and Microsoft.

Related

Modify Lee Mac's Length and Area Field to automatically copy the outputted length to clipboad

I'm using Lee Mac's length and area field to automatically get the total length of an object.
I'm a complete beginner on AutoLisp so I cant find the variable responsible on holding the total length so I can put it in my snippet code to automatically copy it on my clipboard for easy pasting on excel.
Here's my code snippet for automatically putting it to clipboard
(vlax-invoke
(vlax-get (vlax-get (vlax-create-object "htmlfile") 'ParentWindow) 'ClipBoardData)
'setData
"TEXT"
(getvar
)
Since my application uses AutoCAD field expressions to output the length and/or area, the length & area values are not stored in any variable in the code; furthermore, the resulting values displayed by the selected annotation object (which may also be converted to other units and formatted by the field expression) are only available after the field expression has been evaluated.
Given the above, you would need to obtain the text content of the object selected for output after it has been populated with the field expression, before copying such content to the Windows clipboard.
This would involve modifying every branch of my LM:outputtext function to assign the result of evaluating the field expression to a variable which may then be returned by the function and used by the calling function.

SPSS converting a string into a numeric variable issue

I have a string variable with lots of parentheses and other punctuation e.g. _LSC Debt licensed work. How can I easily convert it to a numeric variable when I already have a specified code list for it? i.e. I don't want it to automatically recode everything because it uses the wrong values against the labels.
Create a dataset with two variables: a string holding the current messy name and a numeric variable holding the new code. Then, with both the original dataset and the lookup one sorted by the string, do MATCH FILES specifying a table match (or use Data > Merge Files > Add Variables).
You can prepare a separate file which includes two variables:
- one contains each of the possible values in the original string variable to be recoded (make sure the name and width are the same as your original variable)
- the second contains the new values you want to recode to.
when you set this up, match the files like this:
get file="filepath\Your_Value_Table.sav".
sort cases by YourOriginalVarName.
dataset name ValTab.
get file="filepath\Your_Original_File.sav".
sort cases by YourOriginalVarName.
match files /file=* /table=ValTab /by YourOriginalVarName.
exe.
At this point your original file will contain a new variable that has the codes you wanted.
In general I agree with the solution provided by others. However, I would like to suggest an extra step, which could make your look-up file (see the answer of eli-k and JKP) a bit better.
The point is that your string variable with lots of parentheses and other punctuation probably also has different ways to write the same thing.
For example:
_LSC Debt licensed work
LSC Debt licensed work
_LSC Debt Licensed Work
etc.
You could create a lookup-table with three variables: the unique values of the original string variable, a cleaned-up version of that variable, and finally the numeric value you want to attach.
The advantage of the cleaned-up version is that you can identify more easily the same value although it is written differently.
You could clean up using several functions:
string CleanedUpVersion (A40).
compute CleanedUpVersion = REPLACE(RTIM(LTRIM(UPCASE(YourOriginalVarName))),'_','').
execute.
In this basic example we convert to capital letters, delete leading and trailing blanks and remove the underscore by replacing it by nothing.
Overall this could help to avoid giving different numbers to unique values in your original variable that mean the same thing, while you would like them to have the same number.

How to eval a field name contained in another field in an Access Query?

I need to create a long list of complex strings, containing the data of different fields in different places to create explanatory reports.
The only way I conceived, in Access 2010, is to save text parts in a table, together with field names to be used to compose the string to be shown (see line1 expression in figure). Briefly:
//field A contain a string with a field name:
A = "[Quantity]"
//query expression:
=EVAL(A)
//return error instead the number contained in field [Quantity], present in the query dataset
I thought doing an EVAL on a field (A), to obtain the value of the field (B) which name is contained in field A. But seems not working.
Any way exist?
Example (very simplified):
Sample query that EVAL a field containing other field names to obtain the value of the fields
Any Idea?
PS: Sorry for my english, not my mothertongue.
I found a interesting workaround in another forum.
Other people had same problem using EVAL, but found that it is possible to substitute a string with a field contents using REPLACE function.
REPLACE("The value of field Quantity is {Quantity}";"{Quantity}";[Quantity])
( {} are used only for clarity, not needed if one knows that words to be substituted do not compare in the string). Using this code in a query, and nesting as many REPLACE as many different fields one want to use:
REPLACE(REPLACE("<Salutation> <Name>";"<Salutation>";[Salutation]);"<Name>";[Name])
it is possible to embed fields name in a string and substitute them with the current value of that field in a query. Of course the latter example can be done more simply with a concatenation (&), but if the string is contained in a field instead that hardcoded, it can be linked to records as needed.
REPLACE(REPLACE([DescriptiveString];"[Salutation]";[Salutation]);"[Name]";[Name])
Moreover, it is possibile to create complex strings context-based as:
REPLACE(REPLACE(REPLACE("{Salutation} {Name} {MaidenName}";"{Salutation}";[Salutation]);"{Name}";[Name]);"{MaidenName}";IIF(Isnull([MaidenName]);"";[MaidenName]))
The hard part is to enumerate all the field's placeholders one wants to insert in the string (like {Quantity},{Salutation}, {Name}, {MaidenName}) in the REPLACE call, while with EVAL one would avoid this boring part, if only it was working.
Not as neat as I would, but works.

How to convert a string containing non-numeric values into numeric values?

I have several variables of the form:
1 gdppercap
2 19786,97
3 20713,737
4 20793,163
5 23070,398
6 5639,175
I have copy-pasted the data into Stata, and it thinks they are strings. So far I have tried:
destring gdppercap, generate(gdppercap_n)
but get
gdppercap contains nonnumeric characters; no generate
And:
encode gdppercap, gen(gdppercap_n)
but get a variable numbered from 1 to 1055 regardless of the previous value.
Also I've tried:
gen gdppercap_n = real(gdppercap)
But get:
(1052 missing values generated)
Can you help me? As far as I can tell, Stata do not like the fact that the variable contains fraction numbers.
If I understand you correctly, the interpretation as string arises from one and possibly two facts:
The variable name may be echoed in the first observation. If so, that's text and it's inconsistent with a numeric variable. The root problem there is likely to be a copy-and-paste operation that copied too much. Stata typically gives you a choice when importing by copy-and-paste of whether the first row of what you copied is to be treated as variable names or as data, and you need the first choice, so that column headers become variable names, not data. It may be best to go back and do the copy-and-paste correctly. However, Stata can struggle with multiple header lines in a spreadsheet. Alternatively, use import excel, not a copy-and-paste. Alternatively, drop in 1 to remove the first observation, provided that it consistently is superfluous.
Commas indicate decimal places. destring can easily cope with this: see the help for its dpcomma option. Stata has no objection to fractions; that would be absurd. The problem is that you need to flag your use of commas.
Note that
destring is a wrapper for real(), so real() is not a way round this.
encode is for mapping genuine categorical variables to integers, as you discovered, and as its help does explain. It is not for fixing data input errors.
You can write a for loop to convert a comma to a period. I don't quite know your variables but imagine you have a variable gdppercap with information like 1234,343 and you want that to be 1234.343 before you do the destring.
For example:
forvalues x = 1(1)10 {
replace gdppercap = substr(gdppercap, 1, `x'-1) + "." + substr(gdppercap, `x'+1, .)
if substr(gdppercap, `x', 1) == ","
}

How to find a string within a string

I have the list with like 100,000 site link strings
Each link is unique, but it has consistent ?Item=
Then, it's either nothing or it continues after & symbol.
My question is: How do I pull out the item numbers?
I know replace function can offer similar functionality, but it works with Fixed sizes, in my case string can be different in size.
Link example:
www.site.com?sadfsf?sdfsdf&adfasfd?Item=JGFGGG55555
or
www.site.com?sadfsf?sdfsdf&adfasfd?Item=JGFGGG55555&sdafsdfsdfsdf
In both cases I need to get JGFGGG55555 only
If this always is the last portion of the string, you can use the following:
=MID(A1, FIND("?Item=", A1) + 6, 99)
This assumes:
no item numbers will be over 99 digits.
no additional fields follow the item number.
Edit:
With the update to your question, it is apparent you have some strings with additional data after the ?Item= field. Without using VBA there is not a simple means of using MID and FIND to extract this.
However you could create a column which acts as a placeholder.
For example, create a column using:
=MID(A1,FIND("?Item=",A1)+6,99)
This gets you the following value: JGFGGG55555&sdafsdfsdfsdf
Next, create a column using:
=IF(ISERROR(FIND("&",B2)),B2,LEFT(B2,FIND("&",B2)-1))
This produces: JGFGGG55555 by searching the first value for a & and using the portion before it. If it is not found, the first value is simply repeated.
This formula should work for both the examples given:
=MID(A1,FIND("=",A1),IFERROR(LEN(A1)-FIND("&",A1,FIND("=",A1))-1,LEN(A1)+1-FIND("=",A1)))

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