Background: Participating in an interactive chart project, the customer had a need for polar coordinate comparison to display different types of indicator data in different directions and distances. Specifically, the attribute fields are: Source, distance, orientation, ID, rotation angle, size Let’s look at the renderings first: Technical points: Legend description: The distance is the radial […]
Tag: symbol
stm32 dual machine (f1 and f4) serial communication sends multi-byte symbol number
When I looked for serial port communication information on the Internet, most of it was communication between the host computer and the board. I rarely saw communication between two computers. I will record my thoughts in this article and hope it will be helpful. Interface connection: Select serial port one for f103, select serial port […]
Current status of knowledge representation models – related to symbolic representation
The concept of the Semantic Web was proposed by Tim Berners Lee, the inventor of the World Wide Web, in 1996. The goal is to convert current information into machine-friendly language. The Semantic Web is not an independent network, but an extension of the current network. It empowers The clear meaning of information makes it […]
8.2 A single symbol for vector layer point elements uses one
Article directory Preface Single symbol rendering Simple Marker QGis Code SVG marker QGis Code Summarize Foreword The previous tutorial gave an overall introduction to vector layer symbolization, and took point layers as an example to introduce the renderers that can be used: No symbols Single symbol Category (Categorized) Graduated Rule-based Point displacement Point cluster Heatmap […]
markdown mathematical symbols
Directory title Example approximately equal to inequality sign Less than or equal to, greater than or equal to Not equal to Multiplication sign Click and multiply division sign plus or minus sign endless Sum tiring Greek alphabet arrow Integral, double integral, curve integral Trigonometric functions gradient Because Therefore arbitrariness and existence Belong and not belong […]
ELF: symbol lookup via DT_HASH
referenced:https://flapenguin.me/elf-dt-hash libc.so contains tons of dynamic symbols exported to the outer world ( nm -D /lib/libc.so.6 | wc -l gives 3023 symbols on my machine). And quite a few of them will be imported in any relatively big program. Obviously, doing linear search would be a bad idea. Some sort of a hash table can […]
Driver development based on Linux: kernel module parameter passing, kernel symbol table, character device driver
Kernel module passing parameters Kernel module: int a , b; When installing the kernel module: insmod demo.ko a = 100 b =10; 1. The meaning of kernel module parameters When installing the kernel module, pass values to the variables in the kernel module. This allows our kernel module to be upwardly compatible with more complex […]
[Inter-process communication] Pipe communication {The purpose of inter-process communication; Common methods of inter-process communication; Anonymous pipe: Implementation principle, pipe symbol |, system call pipe, process pool; Named pipe: mkfifo instruction, system call mkfifo}
1. The purpose of inter-process communication Most of the code we wrote before was a single-process task. A single process cannot use the concurrency function of the process, nor can it realize the collaborative work of multiple processes. Therefore, we need to implement multi-process tasks, and the key to multi-process is inter-process communication. Inter-process communication […]
Analyze the address of DLL internal symbols based on PDB file
Recently, I encountered a given DLL file, but I wanted to quickly locate the address of an internal function (not exported). I thought that the Sym series of functions can directly analyze the address of the function based on the known PDB debugging symbol database. By referring to MSDN, we can know what we need. […]
5g PUSCH DMRS symbol location determined
3.3.3 DMRS time domain The parameters involved in the time domain of DMRS are: push.MappingType pusch.FrequencyHopping push.SymbolAllocation pusch_dmrs.DMRSTypeAPosition pusch_dmrs.DMRSLength pusch_dmrs.DMRSAdditionalPosition in, pusch.MappingType determines the range of the first element S and the second element L of pusch.SymbolAllocation Note that the starting symbol of PUS under Type A must start from 0. ! ! ! Next. […]