What is Pdf: Definition and 345 Discussions

Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1993 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. Based on the PostScript language, each PDF file encapsulates a complete description of a fixed-layout flat document, including the text, fonts, vector graphics, raster images and other information needed to display it.
PDF was standardized as ISO 32000 in 2008. The last edition as ISO 32000-2:2020 was published in December 2020.
PDF files may contain a variety of content besides flat text and graphics including logical structuring elements, interactive elements such as annotations and form-fields, layers, rich media (including video content), and three-dimensional objects using U3D or PRC, and various other data formats. The PDF specification also provides for encryption and digital signatures, file attachments, and metadata to enable workflows requiring these features.

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  1. DaveC426913

    Anyone understand modern LinkedIn?

    Changing jobs for the first time in a decade is requiring me to have an up-to-date LinkedIn profile. All my previous content is gone. I guess it expires? Anyway, I should be able to upload a PDF and have it auto-populate my profile - but that function does not work as expected. Here is what I...
  2. ergospherical

    Drawing from a PDF in python

    Some python function f(x) defines an (unnormalised) pdf between x_min and x_max and say we want to draw x randomly from this distribution if we had the CDF F(x) and its inverse F^{-1}(x), we could take values y uniformly in [0,1], and then our random values of x would be x = F^{-1}(y). but...
  3. Hamiltonian

    I Finding the pdf of a transformed univariate random variable

    The above theorem is trying to find the pdf of a transformed random variable, it attempts to do so by "first principles", starting by using the definition of cdf, I don't understand why they have a ##f_X(x)## in the integral wouldn't ##\int_{\{x:r(x)<y\}}r(X) dx## be the correct integral for the...
  4. A

    Good PDF Reading App That Can Bookmark and Annotate?

    I like digital textbooks, and the ones I'm studying now are in PDF format. I really need an app I can use across all my interfaces (windows desktop and laptop, a tablet, and iphone) that I can bookmark and annotate with? I have seen a few readers mentioned online, but it needs to be an app so...
  5. S

    Question about the property of PDF

    This is part of my note: Now, this is practice question: I want to ask why P(X = 2) is not zero, because from the note: P{X = a} = ##\int_{a}^{a} f(x) dx=0## ? If I differentiate F(x), I will get f(x) which is the pdf, then using the pdf to find P(X = 2), I think I will get zero as the...
  6. Y

    Need suggestion on a FREE PDF converter to convert word doc to PDF

    As described. I want to convert word doc to pdf. I know there are free converter online and all. I want suggestion on a safe proven that people here use. Thanks
  7. Wrichik Basu

    Compressing PDF documents to oblivion

    I am applying to several universities for Masters. The universities are asking me to compress all the required documents into a single 5 MB file. I have to submit my 10th and 12th standard marksheets and gradesheets, along with their reverse side. These documents are around 5 MB each because...
  8. T

    Calculus Multivariable calculus PDF books

    Multivariable calculus is a branch of mathematics that extends the concepts of single-variable calculus to functions of multiple variables. In this subject, vectors and partial derivatives are introduced to represent and manipulate multi-dimensional data. The gradient of a function represents...
  9. N

    Please recommend a free pdf book about university-level mathematics for me

    Homework Statement:: Recommend PDF books Relevant Equations:: . Hi, I'm a second-year physics student and my uni doesn't have any study material in the syllabus. Only lectures. I want to learn more. Can you recommend to me a good mathematics pdf book that is about calculus? General topics...
  10. docnet

    Probability problem -- The joint PDF of X and Y is uniform on this rectangle....

    we haven't learned howw to do parts d-f yest. could you please give me a hand? (a) $$E(X)=E(Y)=\int_0^3\int_0^3\frac{1}{9}dxdy=\frac{3}{2}$$ (b)its typoe suppoesed to be W=Y-2 $$E(Z)=E(X-2)=E(X)-E(2)=-\frac{1}{2}$$ $$E(W)=E(Y-2)=E(Y)-E(2)=-\frac{1}{2}$$ (c) i guess joint pdf from ##E(Z)## and...
  11. edfink234

    How to understand Proton Structure-function (pdf)

    I don't understand the attached image, which shows the structure-function of the proton, for the cases of 1. point-like particle 2. 3 non-interacting quarks 3. 3 quarks interacting via gluons 4. valence and sea quarks interacting via gluons Can someone please explain this to me? I would greatly...
  12. SamRoss

    LaTeX Trouble using PythonTex variables in Latex file

    I'm using Visual Studio Code as my text editor. My ultimate goal is to use PythonTex in a Latex file so that I can generate multiple versions of the same worksheet for my class. As a test, I defined a variable myvar = "hi" but I can't get it to render correctly in the pdf when I use \py{myvar}...
  13. N

    A Probability Density Function: Converting Experimental Observations to PDF

    Hi All I am currently doing Master in data science. I came across the function PDF probability density function which is used to find cumulative probability(range) of a continuous random variable. The PDF probability density function is plotted against probability density in y-axis and...
  14. Arman777

    A Calculating the statistical properties of the given PDF

    For instance if we are given only a PDF in the form of ##p(x)##, how can one calculate the characteristic function, the mean, and the variance of these PDF's ? Any site or explanation will be enough for me
  15. Wrichik Basu

    PDF editors for Linux (free or paid)

    I need a good pdf editor for Linux. It can be free or paid. My budget is USD 70. Preferably a perpetual licence. It would be great if the software has a trial version, which will enable me to determine whether it suits my needs. It should have the following capabilities: insert/edit text OCR...
  16. M

    I Probability: why can we use the Dirac delta function for a conditional pdf?

    Hi, I have a quick question about something which I have read regarding the use of dirac delta functions to represent conditional pdfs. I have heard the word 'mask' thrown around, but I am not sure whether that is related or not. The source I am reading from states: p(x) = \lim_{\sigma \to...
  17. iVenky

    I What would the pdf look like for 'N' chess computers with the same rating

    If we have 'N' advanced computers (where N-> infinity) each with exactly the same rating to begin with and make them play with each other for an infinite number of games, what would the shape of the probability density function of the ratings eventually look like?
  18. M

    Help finding some html to pdf converters please

    Hello, I am looking for some softwares that can convert htlm files into pdf and join them. I know Adobe Reader can do this and there are online converters but I am looking for alternatives of Adobe and offline options. Can you please recommend one if you know any? Thank you.
  19. U

    MHB How to find PDF and Expected value of max(x,0), for a random variable x

    Let $a,b,c, \tau$ be positive constants and $x$ is an exponentially distributed variable with parameter $\lambda = 1$, i.e. $x\sim\exp(1)$. \begin{equation} E = \tau\Big[a\frac{1+a}{1+e^{-bx+c}} - 1 \Big]^+ \end{equation} where $[z]^+ = \max(z,0)$ How can I find The PDF for $E$ The...
  20. Y

    Safe way to merge two PDF files

    Hi I need to merge two big pdf files together, as usual when I tried to scan a stack of papers into pdf files, my "beloved" Canon all-in-one determined to make it more interesting for me and jammed a few pages before completing the job. Now I have two files that I want to combine into one...
  21. Y

    Problem opening an Adobe pdf file with my Adobe Reader

    Lately I have been receiving pdf files ( with Adobe sign) that I cannot open with my Adobe reader. I have no problem with all the Adobe pdf I have, just those from that sender. The error message is: When I click OK, I have this message: I tried all the options, got nowhere. Anyone know...
  22. Schwann

    B Can PDF values be equal to zero at some given points?

    Suppose we have a function which looks like this: It seems like it meets criteria of probability density functions: this function is asymptotic to zero as x approaches infinity and also it is not negative. My question is: if at some points this function reaches zero (as I have shown above)...
  23. M

    LaTeX LaTeX editor for outputting pdf equations

    Hi PF! Does anyone know of a LaTeX editor that outputs white equations for powerpoints, etc.? I'm running a Mac, and currently use LaTeXiT, but I can't seem to get this to work for white output.
  24. karush

    LaTeX AP matching PDF using latex

    https://documentcloud.adobe.com/link/track?uri=urn%3Aaaid%3Ascds%3AUS%3A4882882a-63fb-4f57-aefe-154f82d8c04e this a pdf of an attempt to produce AP Calculus matching questions on a PDF I am using overleaf thanks much you might have down load the pdf from the browser then open it in Acobat...
  25. CivilSigma

    Find the PDF in terms of another variable

    Homework Statement For $$f_x(x)=4x^3 ; 0 \leq x \leq 1$$ Find the PDF for $$ Y < y=x^2$$ The Attempt at a Solution So, we take the domain on x to be: $$0\leq x \leq \sqrt y$$ and integrate: $$ \int_0^{\sqrt y} f_x(x) dx = \int_0^{\sqrt y} 4x^3 dx$$ Do we integrate with respect to x or y...
  26. W

    I Joint PDF and its marginals

    Hi all, I was wondering if there exist any theorems that allow one to relate any joint distribution to its marginals in the form of an inequality, whether or not ##X,Y## are independent. For example, is it possible to make a general statement like this? $$f_{XY}(x,y) \geq f_X (x) f_Y(y)$$...
  27. S

    Can't see PDF contents as well as Google does

    There are some PDF files where Google finds keywords, but when I open the link Google gives, the PDF isn't searchable by any tools I've tried ( such as the search feature of Firefox). If I save the PDF to a file, I can't search it with the linux commands grep and pdfgrep. Example...
  28. Ajdin Palavric

    Using PDFs to Compute the Total Cross Section

    Homework Statement I would like to compute the total cross section of a lepton pair production using parton distribution functions. The main problem I am having is the numerical computation and the order of magnitude I am getting as a final answer, which so far definitely indicates that...
  29. T

    Complaint PDF files - download or view

    Since the move to the new servers, many (all?) PDF files have defaulted to Download or Save. Prior to this, as is standard on other sites, PDFs defaulted to View. Rather annoying. Fortunately my browser is configured to Always Ask, but it is still an extra action required. Others have also...
  30. QuantumJames

    A How to take Pz in quasiPDF to infinity to get Light-cone PDF

    When I calculate light-cone PDF by taking pz in quasiPDF to infinity before one-loop integration, I will encounter all the integrations vanish. Such as this integral below: https://imgur.com/8DbDzsV This is from one of one-loop quasiPDF diagram, the sail diagram. The definition is above...
  31. HEPlover

    A Are valence quarks real physical entities?

    Im carefully studying Deep Inelastic Scattering and I have the doubt if valence quarks are real physical entities or if they are just a way we can think hadrons are built. I understand that inside hadron we have the Parton Distribution Functions that say that there are an infinite number of...
  32. M

    I Pdf of Difference of Random Variables

    I want to find the probability density function (pdf) of the difference of two RV's, p_{\Delta Y} = p_{(Y_1 - Y_2)},where y = \sin \theta, and where \theta_1 and \theta_2 are random variables with the same uniform distribution p_{\theta}=\mathrm{rect}\left(\frac{\theta}{\pi}\right). This has...
  33. Z

    LaTeX From CSV to single page PDF

    Hi, I have a really simple CSV with some data that needs to be visualized all together in a single page . The CSV content is basically 4 columns wide with short names and small numbers in the cells so I need to create a layout where the list goes from the up left corner of the page to the...
  34. Mehmood_Yasir

    Pedestrian wait time pdf

    Homework Statement Pedestrian are arriving to a signal for crossing road with an arrival rate of ##\lambda## arrivals per minute. Whenever the first Pedestrian arrives at signal, he exactly waits for time ##T##, thus we say the first Pedestrian arrives at time ##0##. When time reaches ##T##...
  35. Y

    Suggestions for a free PDF reader

    As the title, I need to install a pdf reader. I use PrimoPDF in all my other laptops. BUT when I try to install onto my new Win10 laptop, Norton kept deleting it and said it's not safe. So I need to find another one that is not a scam. Any suggestions? Thanks
  36. jaumzaum

    A PDF of random motion - similar to Browninan motion

    Hello guys, and sorry for my english in advance. I was presented some time ago with the following problem: Suppose there is a frog that jumps in any direction randomly, and all the jumps have size 1. What's the probability of, after 3 jumps, the frog be less than 1 unit from the origin. I...
  37. aquaelmo

    Find the cdf given a pdf with absolute value

    Homework Statement Consider a continuous random variable X with the probability density function fX(x) = |x|/5 , – 1 ≤ x ≤ 3, zero elsewhere. I need to find the cumulative distribution function of X, FX (x). 2. Homework Equations The equation to find the cdf. The Attempt at a Solution FX(x)...
  38. M

    Best PDF readers for windows

    If you are familiar with pdf readers which one do you advise? Which one has the friendly interface and is practical? http://www.techradar.com/news/the-best-free-pdf-reader 1) Adobe Reader 2) Foxit Reader 3) Nitro PDF Reader 4) PDF-XChange Editor 5) Slim PDF Reader 6) Icecream Ebook Reader...
  39. fisher garry

    I Independent versus dependent pdf

    In the green box in the attachment I have calculated the integral of the pdf of 24xy in the same manner as in the theory that leads up to 3.1 in the attachment. But I can't see any difference in that calculation that would explain that if 24xy is dependent why is not also the theory that leads...
  40. D

    MHB Short table of integrals (.tex file) will include pdf of output.

    \documentclass[12pt]{article} \usepackage{graphicx} \addtolength{\textwidth}{1.5in} \addtolength{\hoffset}{-1.in} \addtolength{\textheight}{2.0in} %\addtolength{\voffset}{-1.68in} \addtolength{\voffset}{-0.8in} \newcommand {\rreal}{\mbox{$R\!\!\!\!\!l\,\,\,\,$}}...
  41. C

    Determine whether the PDF converges in distribution

    Homework Statement Let $$ \it{f}(x) $$ be a probability density function. Now let Xn have the density: $$ \it{f}_{n}(x) = n\it{f}(nx) $$ Determine whether or not Xn converges in distribution to zero. (this is the verbatim statement, there is no additional information given)Homework...
  42. Z

    PDF to CDF and Inverse CDF

    Homework Statement I was hoping someone could just verify this solution is accurate. p(x) = 0 , x < 0 4x, x < .5 -4x + 4 , .5 <= x < 1 Find CDF and Inverse of the CDF. Homework EquationsThe Attempt at a Solution CDF = 0 , x < 0 2x^2 ...
  43. fresh_42

    I Free pdf for PDE on AMS Open Math Notes

    To all who are interested in a source for the treatment of partial differential equations: Victor Ivrii, Toronto, Course notes, 310 pages https://www.ams.org/open-math-notes/omn-view-listing?listingId=110703&utm_content=buffer2458a&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer
  44. hmwoodring

    Foundations Seeking 'Higher Math for Beginners' pdf

    Anyone willing to share a pdf of 'Higher Math for Beginners' by Ya. B. Zeldovich ? The link for this text at archive.org seems to be broken for the time being. Many thanks in advance... Harlan
  45. nomadreid

    Adobe Digital Editions takeover of pdf files

    Recently I installed the more recent version of Adobe Digital Editions (the new one is 4.5. I had 3.0 -- in fact, I still have also 3.0, as I am not sure whether I can discard 3.0, since 4.5 took over files from 3.0). But then I saw that many of the pdf files on my computer (which were not Adobe...
  46. R

    Marginal pdf, what am I doing wrong?

    Homework Statement f(xy)=49/8*e^(−3.5*y) 0 < y < inf and −y < x < y 0 otherwise a. Find the marginal probability density function of X, fX(x). Enter a formula in the first box, and a number for the second and the third box corresponding to the range of x. Use * for multiplication, / for...
  47. D

    What is the PDF of the sum of n, iid, non central chi-square

    Homework Statement I need to find the pdf of sum of "n" iid non central chi-square distributed RV's. Homework Equations The PDF of the non-central chi-square RV is given herehttps://en.wikipedia.org/wiki/Noncentral_chi-squared_distribution The Attempt at a Solution i tried to find the...
  48. K

    A Integral of squared univariate PDF

    Hi all, I was trying to find an answer, but couldn't, what is the integral of the squared probability density function? It doesn't seem to be equal to the square of cumulative distribution function, but how to tackle it? ∫(f(x))2dx = ? Can we transform it into, say, ∫f(x)dF(x)? and then...
  49. T

    Need to convert .f90 file to pdf

    Hi guys, I am currently having a problem in converting, my .f90 and .txt and output files into a single pdf. Dose anyone have any ideas?
  50. doktorwho

    LaTeX Top iOS App for Creating PDFs with LaTeX | Texpad & Texwriter Alternatives

    hi, do you happen to know any app for iOS that can create pdf-s by writing LaTeX. I know of Texpad and Texwriter but don't know if they can create pdf-s from the code you write. Any help?